He is, and Clichy maybe aswell, the difference is only that for the past year Evra's had a reason to burst forwards and get crosses in, Clichy doesn't really get on the overlap and cross it in anymore, as Arsenal just can't play that football without a willing/fighting runner to get on the end. Likewise Chelsea aren't the same team as a year or two ago, mostly Cole has Kalou, or Joe "hogs the ball, cuts inside and shoots" Cole so he doesn't have someone to play the left wing with, like earlier at Chelsea or like with Henry/Pires to play off.
Evra is the most effective at the moment, because the team around him complementing his position is FAR better than other left backs, that doesn't actually make him better though. I think Cole's probably the best around, or he certainly was a few years ago. Each on their best day I wouldn't think theres much between Cole/Evra/Clichy, all three are VERY very good and if you had any of the three you wouldn't bother buying anyone in to replace them as you'll find no one noticeably better in the world.
The only thing is you could say Evra's the most composed infront of goal than the other two. But I don't really think it counts against Cole/Clichy for barely ever scoring because you don't really need it from a a left/right back.