Report of my experience using akmenu4 AK_AIO_1.1r2 BETA 2008.08.06 (this is not the original nor the oficial name) with the AKRPG:
Copy, Cut, Paste and Delete: working.
1456 Legend of Zelda - Phantom Hourglass, The (US): working (saves, loads, etc., save created with this firmware)
2252 World Ends With You, The (US): working (save created with this firmware).
2359 Soul Bubbles (EU): working (save created with this firmware).
Any other game I was playing before updating to AKAIO: working (save recognised, etc.).
Any other game I was playing with other flashcard (R4): working (save recognised and "trimmed").
Booting AKRPG without memory card: working.
Booting AKRPG with 4GB MicroSDHC: working.
Running NDS games: working.
Opening "Cheats" window (Y, touch Cheats button - usrcheat.dat): working (with 1.1, it froze, but I only tried one time).
Running GBA games: Not working. It seems to write the save to PSRAM, but doesn't boot the game.