I'm not one for knee jerk evaluations or statements, but watching the games this weekend, it's clear to me that Merriman is better. Don't get me wrong, I love Ware and am completely satisfied with the pick.
Merriman has a motor that is always running at maximum horse-power. Every play it looks like he's going to kill somebody.
Ware is great in space, and I'd rather have him chasing a guy down from behind, but as has been stated many times before, he lacks Merriman's fire (popular to say a "mean streak").
That being said, the reason I'm happy with the pick is because I think Ware has more upside. He's more raw than Merriman, but I think his measurables are freakish... moreso than Merriman. If Ware gets the most out of his measurables, he'll end up better.