The thing I liked about old Clark, personally, was that he was ALL about throw mix-ups. I also hated this, though; If you didn't master getting into the enemies head + knew exactly what move or movement to do, to counter each situation, Clark felt like a gimped Ralf.
Ralf fit the combo style of KoF, and had the AB. So many other grapplers seemed like a better take on what Clark wanted to be, for KoF, so the only reason to like Clark was because you liked HIM, lol. I did like his Multi-part throw style a lot, but Mary or Shermie did about the same, but a bit better.
Notice I'm not saying "This is all he was". I'm just speaking for how he felt to me, as a character.
I rather liked him in the MI games, however. In MI, everyone had combo and setup power. He felt as if the game's systems made him a more well-rounded character.
And then we have KoF XII. I didn't like that Clark, the master of throwing, had only 1 real throw here. His multi-branch throws are his trademark, and th only thing that survived was flashing elbow! Also, he had the worse throw range of any of the grapplers. Raiden and Goro had much better hit confirm throws, even Elisabeth did better at grappling than him!
I did, however, like the hop they gave him. At it's best, it should replace the mixup his run-throws gave him. It's too slow to combo with, but fast enough to follow a backroller, and punish them out of that.
In XIII, I feel he's expanded well as his own person, but not as much as I'd like. I think the new Ultra Guardpoint AB should now give him a bit of his old "frankenstiener on wakeup" trickery back, which I'm very happy with, and I agree mAsTarOth, he has better combo options than ever. He also does very nice damage when he LANDS a backbreaker, but compared to the big drive-cancel /HD mode people of the game, he feels like he stops earlier. So while his base combo potential might be higher, I don't know if it evens out, in the end?
Even if they just made him able to attack with some air attacks out of foward hops, as other can out of back-hops, I think that'd return some of the "rushing, mobile grappler" feel to him. I don't ENTIRELY miss the feeling though, since Maxima seemed to almost take the spot from Clark entirely now...
I hope we find some more stuff out about Clark changing on console, though. I would have been happy with 1 press of Super Argentine Back Breaker turning into a running start-up variation, so he could combo/super cancel it after gattling attack juggles... I don't think the combo'n after EX flashing elbow would be too much to ask, either, as I think it'd be a perfect tool if balanced similiarly to Vice, with limited followups.