Hm I have level 29 blaster and now 23 corruptor.
Seems that corruptor is far easier to at soloing. And generaly harder to be put down then blaster.
As for PvP in 1 on 1 situation mayeb thats true that those two archetypes balance them self. But I alos have feeling that blaster needs to much more skilled then corrutor to win. The more hits blaster takes the less chances he/she have to win. While for corruptor (with self heals) it aint making that much differance IMO.