It will work with class-2 and class-4, but there's concerns because read speed is what's important, while class dictates write speed... so the class isn't always an indicator of how well a microsd works. That said, the higher-class carts tend to be built better than the lower-class ones, which is why people suggest going for a class-4 or class-6.
hi i really wanted to know afew things about this R4(on a 3ds) :
-can it play 3ds roms? No
-can it some how also play GBA roms with any homebrew? There is this homebrew, but it's not very good. I suggest looking into a Supercard DStwo or Ez-Flash IV for GBA roms.
-can it run that Snes emulator for NDS with the game: super mario RPG(got a old R4 for NDS but that one can´t run it) No, even the DSTWO's CATSFC, has problems emulating Mario RPG.
-can it watch movies without needing to convert to a other file format just for a NDS but play like AVI files No.
Yes. For updates and info on recent things, it's best to check on the actual site.Does it support 3DS 4.3.0-10?
Well it's pretty much the recommend budget card nowadays, since the AK2i's updates have slowed.It seems very good.