The Zero's were among the most manueverable planes of WWII. Pilot tactics proved much better on the Allied side, of course.
I'm a big Flying Tigers fan and I know for a fact that the P-40 Warhawks were no match for the Oscars(often mistaken as the Zero fighter) in every way except for two imortant things - diving speed and armor protection. They used these two qualities to their advantage. BTW, the Oscar was also manufactured by Nakajima.
IMO, the Zero was just as agile(but not as fast) as the P-51 Mustang and the Me-109.