Yep, I've been playing it for just under a month. I quite like it; it's not got anywhere near as much story as normal FF games, but that's not entirely unexpected; it's a GBA Tactics game, after all, and I'm not that far into it yet either (I've freed 2-3 areas out of 30). The combat system works quite well, and the Laws can make battles pretty interesting - every now and then you'll get a battle where you can't use your most powerful character for some reason. (Of course, I've just got some anti-laws so I think now I can start playing about with what's forbidden or otherwise in battles...)
So, yeah, it's a pretty good game; pity I can't get FF6 for my SP, because I think that'd be better (actually, I should really see if anyone has tried doing that...), but it's better than most games, I reckon.