What are the major benefits of playing it on SNES?
It's the original, unmodified game as it was intended to be played originally.
Maybe it's just my imagination, but the controls seem to lag a little bit on the GBA to me. I don't know how to explain it...the touch is different for when you move the cursor around and go into menus and stuff. FF6A has the same kind of ...'sluggishness' to it.
I didn't notice this much in FF5A and FF6A, but in FF4A this is definitely very noticeable, and it really feels bad.
Also the SNES version is not zoomed up to heck.
The biggest change (which is probably what you're trying to specify) is that GBA has lower resolution, and as such, you can see less when travelling.
Blame TOSE. The music engine in the GBA version is poorly coded so it's generating so much lag.
Actually it's not the music engine but the rest of the game which was badly coded by TOSE. The music engine was coded by Nintendo, as with 90% of GBA games. But since the music engine intentionally takes a significant amount of CPU time (the GBA was designed that way), it's possible to partially compensate by bad coding for the rest of the game by making the music engine very fast.
Hearing the amazing soundtrack in its non-butchered form! (Though the GBA restoration patch by Bregalad is wonderful too)
Thanks ! It seems this very hack makes my hack mostly obsolete for english natives, though.