Pires was better than Vieira and only second best to Henry due to longevity and the sheer amount of goals Henry scored, Pires could do things Henry could only dream of. Pires was also surprisingly strong and had a great first season and throughout he was just immense from his second season onwards. He didn't run his contract down, he left after being subbed in the CL final rather than taking off the woefully ineffective Hleb. All season long Wenger prefered Hleb to either Reyes or Pires and dropped Reyes for the final and took Pires off, both left because of that decision, it was the final nail in the coffin on their Arsenal career's, and both were so much better than Hleb it was embarassing.
Pires was one of the all time best players ever at Arsenal, in the league and one of the best left wingers the world has seen, creativity wise he's basically unmatched, if he had Gigg's/Ronaldo pace he'd probably have been regarded as one of the best players in the world.
INjuries did hold him back, but not much, he's been fantastic at Villareal in all but his first season where he picked up one of the seemingly common foot stuck in the turf ACL injuries, out for 4/5 of the season and was by far their best player in the final 1/5 of that season.
Arsenal need 3 or 4CB's considering Djourou is crap, Senderos is almost certainly good, Silvestre HAS to leave and Gallas is 80% likely to leave, basically leaving Vermaelen and Campbell. We need a world class CB, and a couple of back up types, with one preferably being much better than the quality of back up we have now.
We need a DM, or two, some real wingers, and to go back to 4-4-2.
The idea of buying Chamakh, when we play a 4-5-1, and have 5 strikers(RVP, Bendter, Theo, Eduardo, Vela) and Nasri, Arshavin, Rosicky, Ramsey, Wilshire who all prefer to play as advanced central players, buying another striker is a joke.
EDIT:- The one and only time I wish Pires wasn't an Arsenal player, was the "numb foot" penalty incident,

It was really god damned funny though.