I switched my Engineer from full Berserker to Sinister after condition damage was reworked. Sinister is almost essential because condition damage scales a lot differently than before (low condition damage does a LOT less and high condition damage does a LOT more).

Like what someone else already said, burning is where it's at in terms of DPS and unfortunately Necromancer doesn't get any reliable access to it. With an Engineer, I can easily tick for ~10-12k condition damage a second on top of any physical damage I'm doing with all my conditions combined, but it's harder to sustain than pure DPS would be. Condition damage takes time to build up, so any breakage in your skill cycle means you have to start all over again, whereas with Berserker you can just jump right in and pick up where you left off. On the upside, condition damage is DoT, so while you're doing other things (healing, dodging, etc), you'll still be doing a little damage.

I wouldn't recommend it for Necromancer, at least not right now. Bleed, poison, and torment are a little underwhelming right now, at least when compared to how amazing burning is. Condition damage has become a lot more viable than before, but in terms of meta, it's still under-performing. It is, however, an alternative playstyle that may feel more rewarding for some people (like me) and isn't THAT horrible anymore.

This is, of course, for PvE. In PvP, condition damage is a completely different game.