I don't think we can say that Wilshere puts in better performances consistently. He played almost all of 10-11 and was understandably inconsistent given that it was his first season at the top. The fact that he put in some superb individual performances (Barca at home and the CC Final against Birmingham) has somewhat clouded the fact that there were quite a few games that season where he struggled to make a huge impact. That doesn't mean he didn't have a good season (indeed, he performed infinitely better than Theo did in his first full season at Arsenal) but he wasn't consistently 7-8/10. Then, he got injured and missed all of the next season and has only just returned this year, where again he's been very good some games, decent/off colour in others which is again understandable.
Earlier in thread it's been said that Wilshere is given £80K/week because of future potential, and I agree with that (same with Theo, even if you think Wilshere will be the better footballer Theo's past productivity and progression suggests he'll continue to be a very important source of goals/assists for us). However, if the argument is that Wilshere deserves more because he has played better than Walcott on a consistent basis so far at Arsenal, IMO that doesn't ring true at all. Over the last 2 seasons Walcott has been one of the most consistent performers at the club.
Theo is currently way ahead of Jack. We love Jack because of his heart on sleeve attitude, but he is still young, and green at times on the pitch.