First of all, thanks to the OP and others for their contribution.
I'm switching from DPS to Tank, and it helped me a lot.
Otherwise :
I played up to the 50 level almost alone as an Infiltration DPS, and i never encountered a fight when i said myself '**** i should've gone with tank spec'
Shadow Dps is awesome. You can in general deal with enemies way before you'll have to worry for your health bar.
Later on, when you'll have the healer pet, with all trinkets and CCs you have, it even becomes easy mode
You can easily deal with H2+ instances / Epic mobs alone.