Lets just update this, shall we?
Your welcome first of all.

Link to the most recent custom firmware with customizable menu: 3.03 OEC
Link to the most recent custom firmware period: 3.10 OEA

Link to a tutorial on downgrading/upgrading to Dark_AleX's custom firmware:
Pimp my PSP! (1.50 + 3.03 Firmware on the same psp)

PSP default firmware > What to go to > where you can end up.
1.00>1.50>
~~~~~~>2.71 SE (A, B, B', B'', C)
~~~~~~>3.02 OE (A, B)
~~~~~~>3.03 OE (A, A', B, C)
~~~~~~>3.10 OE (A, A')
1.51>2.71>2.71 HenD>1.50>
~~~~~~~~~~~~~~~~~>2.71 SE (A, B, B', B'', C)
~~~~~~~~~~~~~~~~~>3.02 OE (A, B)
~~~~~~~~~~~~~~~~~>3.03 OE (A, A', B, C)
~~~~~~~~~~~~~~~~~>3.10 OE (A, A')
2.00>2.71>2.71 HenD>1.50>
~~~~~~~~~~~~~~~~~>2.71 SE (A, B, B', B'', C)
~~~~~~~~~~~~~~~~~>3.02 OE (A, B)
~~~~~~~~~~~~~~~~~>3.03 OE (A, A', B, C)
~~~~~~~~~~~~~~~~~>3.10 OE (A, A')
2.01>2.71>2.71 HenD>1.50>
~~~~~~~~~~~~~~~~~>2.71 SE (A, B, B', B'', C)
~~~~~~~~~~~~~~~~~>3.02 OE (A, B)
~~~~~~~~~~~~~~~~~>3.03 OE (A, A', B, C)
~~~~~~~~~~~~~~~~~>3.10 OE (A, A')
2.50>2.71>2.71 HenD>1.50>
~~~~~~~~~~~~~~~~~>2.71 SE (A, B, B', B'', C)
~~~~~~~~~~~~~~~~~>3.02 OE (A, B)
~~~~~~~~~~~~~~~~~>3.03 OE (A, A', B, C)
~~~~~~~~~~~~~~~~~>3.10 OE (A, A')
2.60>2.71>2.71 HenD>1.50>
~~~~~~~~~~~~~~~~~>2.71 SE (A, B, B', B'', C)
~~~~~~~~~~~~~~~~~>3.02 OE (A, B)
~~~~~~~~~~~~~~~~~>3.03 OE (A, A', B, C)
~~~~~~~~~~~~~~~~~>3.10 OE (A, A')
2.70>2.71>2.71 HenD>1.50>
~~~~~~~~~~~~~~~~~>2.71 SE (A, B, B', B'', C)
~~~~~~~~~~~~~~~~~>3.02 OE (A, B)
~~~~~~~~~~~~~~~~~>3.03 OE (A, A', B, C)
~~~~~~~~~~~~~~~~~>3.10 OE (A, A')
2.71>2.71 HenD>1.50>
~~~~~~~~~~~~~>2.71 SE (A, B, B', B'', C)
~~~~~~~~~~~~~>3.02 OE (A, B)
~~~~~~~~~~~~~>3.03 OE (A, A', B, C)
~~~~~~~~~~~~~~~~~>3.10 OE (A, A')
2.80>2.80 HenD for 2.80>1.50>
~~~~~~~~~~~~~~~~~~>2.71 SE (A, B, B', B'', C)
~~~~~~~~~~~~~~~~~~>3.02 OE (A, B)
~~~~~~~~~~~~~~~~~~>3.03 OE (A, A', B, C)
~~~~~~~~~~~~~~~~~~>3.10 OE (A, A')
2.81>3.03>3.03 with GTA:Liberty City Stories UMD unpatched>3.03 downgrader>1.50>
~~~~~~~~~~~~~~~~~~>2.71 SE (A, B, B', B'', C)
~~~~~~~~~~~~~~~~~~>3.02 OE (A, B)
~~~~~~~~~~~~~~~~~~>3.03 OE (A, A', B, C)
~~~~~~~~~~~~~~~~~~>3.10 OE (A, A')
2.82>3.03>3.03 with GTA:Liberty City Stories UMD unpatched>3.03 downgrader>1.50>
~~~~~~~~~~~~~~~~~~>2.71 SE (A, B, B', B'', C)
~~~~~~~~~~~~~~~~~~>3.02 OE (A, B)
~~~~~~~~~~~~~~~~~~>3.03 OE (A, A', B, C)
~~~~~~~~~~~~~~~~~~>3.10 OE (A, A')
3.00>3.03>3.03 with GTA:Liberty City Stories UMD unpatched>3.03 downgrader>1.50>
~~~~~~~~~~~~~~~~~~>2.71 SE (A, B, B', B'', C)
~~~~~~~~~~~~~~~~~~>3.02 OE (A, B)
~~~~~~~~~~~~~~~~~~>3.03 OE (A, A', B, C)
~~~~~~~~~~~~~~~~~~>3.10 OE (A, A')
3.01>3.03>3.03 with GTA:Liberty City Stories UMD unpatched>3.03 downgrader>1.50>
~~~~~~~~~~~~~~~~~~>2.71 SE (A, B, B', B'', C)
~~~~~~~~~~~~~~~~~~>3.02 OE (A, B)
~~~~~~~~~~~~~~~~~~>3.03 OE (A, A', B, C)
~~~~~~~~~~~~~~~~~~>3.10 OE (A, A')
3.02>3.03>3.03 with GTA:Liberty City Stories UMD unpatched>3.03 downgrader>1.50>
~~~~~~~~~~~~~~~~~~>2.71 SE (A, B, B', B'', C)
~~~~~~~~~~~~~~~~~~>3.02 OE (A, B)
~~~~~~~~~~~~~~~~~~>3.03 OE (A, A', B, C)
~~~~~~~~~~~~~~~~~~>3.10 OE (A, A')
3.03>3.03 with GTA:Liberty City Stories UMD unpatched>3.03 downgrader>1.50>
~~~~~~~~~~~~~~~~~~>2.71 SE (A, B, B', B'', C)
~~~~~~~~~~~~~~~~~~>3.02 OE (A, B)
~~~~~~~~~~~~~~~~~~>3.03 OE (A, A', B, C)
~~~~~~~~~~~~~~~~~~>3.10 OE (A, A')
3.10>Not possible yet.

Also, if you have TA-082 or TA-086:
2.00>2.80>2.80 HenD for 2.80>Id File Storage Hack>1.50>
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~>2.71 SE (A, B, B', B'', C)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~>3.02 OE (A, B)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~>3.03 OE (A, A', B, C)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~>3.10 OE (A, A')
2.01>2.80>2.80 HenD for 2.80>Id File Storage Hack>1.50>
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~>2.71 SE (A, B, B', B'', C)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~>3.02 OE (A, B)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~>3.03 OE (A, A', B, C)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~>3.10 OE (A, A')
2.50>2.80>2.80 HenD for 2.80>Id File Storage Hack>1.50>
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~>2.71 SE (A, B, B', B'', C)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~>3.02 OE (A, B)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~>3.03 OE (A, A', B, C)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~>3.10 OE (A, A')
2.60>2.80>2.80 HenD for 2.80>Id File Storage Hack>1.50>
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~>2.71 SE (A, B, B', B'', C)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~>3.02 OE (A, B)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~>3.03 OE (A, A', B, C)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~>3.10 OE (A, A')
2.70>2.80>2.80 HenD for 2.80>Id File Storage Hack>1.50>
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~>2.71 SE (A, B, B', B'', C)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~>3.02 OE (A, B)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~>3.03 OE (A, A', B, C)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~>3.10 OE (A, A')
2.71>2.80>2.80 HenD for 2.80>Id File Storage Hack>1.50>
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~>2.71 SE (A, B, B', B'', C)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~>3.02 OE (A, B)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~>3.03 OE (A, A', B, C)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~>3.10 OE (A, A')
2.80>2.80 HenD for 2.80>Id File Storage Hack>1.50>
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~>2.71 SE (A, B, B', B'', C)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~>3.02 OE (A, B)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~>3.03 OE (A, A', B, C)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~>3.10 OE (A, A')
2.81>3.03>3.03 with GTA:Liberty City Stories UMD unpatched>3.03 downgrader>1.50>
~~~~~~~~~~~~~~~~~~>2.71 SE (A, B, B', B'', C)
~~~~~~~~~~~~~~~~~~>3.02 OE (A, B)
~~~~~~~~~~~~~~~~~~>3.03 OE (A, A', B, C)
~~~~~~~~~~~~~~~~~~>3.10 OE (A, A')
3.00>3.03>3.03 with GTA:Liberty City Stories UMD unpatched>3.03 downgrader>1.50>
~~~~~~~~~~~~~~~~~~>2.71 SE (A, B, B', B'', C)
~~~~~~~~~~~~~~~~~~>3.02 OE (A, B)
~~~~~~~~~~~~~~~~~~>3.03 OE (A, A', B, C)
~~~~~~~~~~~~~~~~~~>3.10 OE (A, A')
3.01>3.03>3.03 with GTA:Liberty City Stories UMD unpatched>3.03 downgrader>1.50>
~~~~~~~~~~~~~~~~~~>2.71 SE (A, B, B', B'', C)
~~~~~~~~~~~~~~~~~~>3.02 OE (A, B)
~~~~~~~~~~~~~~~~~~>3.03 OE (A, A', B, C)
~~~~~~~~~~~~~~~~~~>3.10 OE (A, A')
3.02>3.03>3.03 with GTA:Liberty City Stories UMD unpatched>3.03 downgrader>1.50>
~~~~~~~~~~~~~~~~~~>2.71 SE (A, B, B', B'', C)
~~~~~~~~~~~~~~~~~~>3.02 OE (A, B)
~~~~~~~~~~~~~~~~~~>3.03 OE (A, A', B, C)
~~~~~~~~~~~~~~~~~~>3.10 OE (A, A')
3.03>3.03 with GTA:Liberty City Stories UMD unpatched>3.03 downgrader>1.50>
~~~~~~~~~~~~~~~~~~>2.71 SE (A, B, B', B'', C)
~~~~~~~~~~~~~~~~~~>3.02 OE (A, B)
~~~~~~~~~~~~~~~~~~>3.03 OE (A, A', B, C)
~~~~~~~~~~~~~~~~~~>3.10 OE (A, A')
3.10>Not possible yet.

Benefits of 1.50:
~Homebrew, emulators, and other unsigned code can be run from the game/memory stick menu.
~Smaller in Flash0 without modification.
~Great for upgrading to 3.03 OEC.
~Lots of tutorials.

Cons of 1.50:
~Need to use homebrew to emulate higher firmwares to play demos, UMD's, etc.
~Can not run 1.00 or 2.00 homebrew without knoxploiting it.
~No internet browser, media visualizer, rss, ps3 connection, etc.

Benefits of Dark_AleX's Custom firmwares: (Specifically 3.03 OEC)
~Can use all of 1.50 homebrew, 1.00 homebrew, and 2.00 homebrew
~Has folders that run using either the 1.50 engine (For homebrew) and the 3.03 engine (for demo's, etc). This means no input needed, and all homebrew appears under Game, Memory stick.
~Can back up games for faster load times, and place in /ISO to make them show up under Game, Memory stick like homebrew.
~Can overclock the menu and games to 333, works with wifi now.
~Can access flash0 and flash1 via usb, for customization and recovery.
~Has recovery menu to save most errors, and recover data. Can also hack registry to activate flash and wma.
~Video can be played full screen.
~Can convert any Playstation game into a PSP game (See AutoPopstation4)
~Can connect to PS3, has browser, visualizations, all that firmware 3.03 has.
~Can be upgraded to using legal Eboot.pbp updates from sony, converted.
~Boot time has been reduced by 3 seconds from earlier custom firmwares
~More control (Such as skipping the intro, region free UMD's, Auto Boot, etc)
~When formating memory stick, this creates all folders needed (/iso, /psp/game303, etc)
~Has tutorials and people willing to help.
~More, just can't think of them right now.

Benefits of Dark_AleX's Custom firmwares: (Specifically 3.10 OEC)
~PAL for PS1 games fixed, other neat stuff
~Change from 3.03 firmware to 3.10
~4th level of brightness (aka battery eater) can now be selected also without ac adaptor.
~Changes in hen core:
~Static user elf's can now be executed in the 3.10 kernel.
~Tyranid's patch (added in 3.03 OE-C) consequences was not explained very well in the changelog of 3.03 OE-C:
~For programmers: kernel modules have user imports, making kernel programming in 3.03/3.10 less strict.
~For users: plugins and apps that worked in 2.71 SE, but not in OE, *may* work in 3.03OEC and 3.10 OEA.
~Most recent, can play games rigged to only allow 3.10.

Cons of Dark_AleX's Custom 3.10 OE firmwares:
~As of this moment, only 3.03 OE and below can customize the main menu's text and icons.
This is being worked on for 3.10 OE, but it is not ready just yet.

Cons of Dark_AleX's Custom firmwares:
~Due to using parts from both 1.50 and 3.03, and from adding a recovery menu, flash0 has less room by default. Some programs create more room by disabling/removing other languages, but by default custom firmwares have less room.
~Due to how fast Dark_AleX can make these things, some homebrew takes a while to be upgraded to work with it.
~You have usb access to Flash0 (your OS) and Flash1 (your Ram). Do not mess with this. Please. A lot of noobs are going to delete flash0, I just feel it. Dont be one of them.
~Sometimes when upgrading from custom to custom instead of going through 1.50, your flash1 gets corrupted (UMD games don't play, etc). To fix it, you can format flash1. Only flash1. Please.
~Your fingers bleed from playing games for too long.

^_^ I will try and update this in a timely matter. I wish there was a way to joint create threads, so several accounts could alter them as needed... oh well.

__________________