TA is actually a pretty good controller secondary. Don't believe all you hear. (However avoid Poison Gas Arrow ATM, it's bugged).
In theory the perception debuffs should stack, however the perception debuff on Flash Arrow is pretty substantial anyway.
I really should do something about this signature.
Tried it out a bit now, seems to make peeling off minions very effective with doubled smoke and flash arrow.
Just rolled a Fire/TA troller for concept reasons (not a min/maxer) and enjoying him. Looking foward to slick arrow and igniting it (*lvl 35.. sigh*).
I have got Smoke AND Flash Arrow, and they SEEM to stack together, allowing single target pulls from mobs fairly easily.
Can anyone confirm if the perception debuffs do indeed stack?