Supercard micro-SD works only with SD cards of up to 2 GB, but you can always use more than one. Again, and I repeat, I have tried all F.E. 7/8 complete hacks, and the saves (even about Vision Quest) work without any problems when placed each in its own folder. Regarding EZ Flash Omega, some GBAtemp users have reported that Vision Quest fails to save. If you are only interested in F.E.hacks then the former is sufficient; if you are interested in all GBA games, I recommend EZ Flash Omega.
This is my opinion, whether anyone likes it or not.