He had an outstanding season last year, but his previous two seasons, while fine, weren't particularly memorable and had lows as well as highs. For that reason, I wouldn't put him above the likes of Bergkamp and Pires.
If he can put together another season of exceptional quality, he will make a real claim of lasting legacy at Arsenal. We all know he has the talent, but hopefully he manages to maintain the right attitude if we don't challenge, as I do think his temperament seems a bit questionable at times