I've only done them on my thief up to this point. She has a very well planned out approach, does a lot of damage, is rarely in trouble and feels like she supports the team really well. I took my warrior in to level 1 tonight, and I felt like I was constantly lacking appropriate skills to use.
My warrior is specced max in to power, and the rest split between CD and precision lines. I have most of the weapons available as exotics or rares and I prefer to be damage oriented... should I forget that mentality and buy a shield?
Maybe it's the slots skills I wasn't using properly, although I can't really see a good alternative to most of them. FGJ seems like a must have and the elite signet is the best elite as far as I can tell. I was also using the one that makes you invulnerable.