if you can get a nice rebuild? ZA50 they have far more potential, then again i havent kitted one. give me a few weeks, im prolly gonna destroy it if i havent yet.
E50's are industructible, fast, awesome, unlimited parts supply.
if you have the money and want a 70mph beast, ZA50, if you plan on riding your ped alot, and dont want alot of work, e50 by far.
go for a a35/a55 haha!~SABAT!