I don't know mate, i play infiltration shadow since the game launch and i never have trouble with any class in any 1vs1 except shadow kinetic.
I'd never use anyway the low slash after the first clairvoyant strike, id keep it for interrupt when mind snap is on cooldown or use it to land a backstab proc if the nemy player is smart or even to run away.
The only class that could make us die is balance sage but it takes way too long to kill someone that you can still vanish if you see you really losing.
Referring to the damage output we might not doing the same damage as a sniper or a commando, but we still have the best single target burst when we want, and a healer disappears when we are on it. Honestly i don't feel underpowered even if i would love some more dps considering how squishy we are.