imho the best KoFs to play competitively would be.. 98 (the favorite for the Chinese players), 2002 UM (arcade version, which has some differences compared to the PS2 version) and XI (there are some good match vids for 95, and some say that 99 is well-balanced)
so far I'm worried about the actual movelists (the hypothetical moves that weren't published in that movelist sheet), and that normal moves (standing strong punch, for example) would still be the same no matter if you were close to your opponent or not. Also, I don't like one super per character (with few known exceptions being Ryo and Robert)..
I'm hoping that Ryo, Clark and Ralf are good enough in this version (I like Ryo's forward+light kick move, the hqf+kick and his 2x(hqf)+punch moves, Clark's command throw wasn't much useful in XII besides being part of combos and Ralf's lost his down, up+punch, his weak Ralf Kick and Ralf Tackle)
It seems that both dodge types are present (the Extra's A+B, and Advanced's forward/backwards A+B), there are "break shots" (C+D during blockstun) and rolling guard cancels (A+B during blockstun) like the previous games, a guard gauge (like 2002 UM), no clash system (it was nice in Treasure's Yuu Yuu Hakusho fighting game for the Mega Drive, however, being able to stop a super with a normal move that way, more like by accident, sounds silly imho), no [strike]SFA2 Custom Combos[/strike] [strike]silly waiting game[/strike] Critical Counter, and no "focus system" (while the idea was interesting, I didn't like how KoF XII tried to feel like SFIV, it was weird to feel the gameplay, unlike when you play Garou and then 3s). Also, no zoom (which I think worked well in a slower paced game like AoF, or was better implemented in the Samurai Shodown series, but not in XII).
What I would like to see, too, is rolling cancels after attacks (first implemented in 2002), and HSDMs (supers to use when you're low on life). Also, more characters (meaning, more playstyles) and alternative character versions (the same here, though this can be compensated by merging movelists from the affected characters) would enrich the gameplay, but these two would be a bit unrealistic for me to ask..