I don't think it's right to compare ourselves to Powertechs...
Mercenary just have a different play style that works fine in PvE, but is a bad joke in PvP and this is not PT fault, I swear!
Currently Mercs just lack the tools/utilities for a competitive PvP, and can be easily disabled. No matter where I go I always seem to be "1st priority target" since Merc just goes down easily...
Personally I think, at least Arsenal, needs to have a temporary "Interrupt immunity" or "cast shortening" (like sorcs) in form of a buff, sounds fair since we don't get a Interrupt like every other class around...