He does a great job playing the enforcer role for Evolution.
The only knock on Batista is his wrestling ability and his age. The ladder can be forgiven, but Batista has shown himself to blow major spots. Hopefully, he can improve on his ring abilities soon.
On the mic, Batista carries himself VERY well and his mannerisms are superb. Notice the look he gave when he flashed Eugene a thumbs up, instead of shaking his hand. Also, when he pushed Kane's head aside, or the time he stood face to face with Kane during the Battle Royal. Or the time he beat Tajiri just by choking him (just look at his expression while he was choking Tajiri). Batista isn't a chicken shit heel, and he doesn't ever back down. Fans can respect him for that, which is why the likely cheered him on Raw.
Batista shouldn't be Evolution's job boy because that is the way he is being used in the last couple of weeks. Instead, let him continue his monster role. In all seriousness, I can imagine him as the WWE's version of the WCW Scott Steiner (when he was the Big Bad Botty Daddy).
If a Evolution break up is to happen, look for Batista to get more over than any other member. I'm serious, the guy has great potential.