This used to all be true, but after B31 and various devotion changes, I would say melee Spellbreaker > PB spellbreaker, Witch Hunter now has very good survivability with the damage absorb on Posession and Blood of Dreeg + the raven. All classes need some degree of resistance debuff on Ultimate to keep up their DPS.
Saboteur is very flavour of the month at the moment and also very good in this game build! Just put lots of points in to the Fire Stike & Dual wield line with other points as you feel you need in other skills such as Pneumatic Burst, Flame Touched, Vindictive Flame & Blast Shield
Very easy to gear as well…I am playing a ‘self-found’ Saboteur atm, currently lvl 60 using mostly lvl 50 faction vendor gear and a few random epics and still using Sanctuary relic that I made at lvl 18!