Well it was never hard for me to play. I'm not saying the class isn't underpowered though, because it is (if you compare it to other classes) - for example I had a much easier time clearing mobs in PvE on my BH Mercenary.
It's just that there's several factors that make your life easier when leveling.
For example I was ALWAYS 2-3 levels above content, I'm lvl 39 now and on Quesh and the mobs go down before they can do significant damage.
Also, I'm using Doc. Finishing most fights on 100% hp.
I keep gear updated.
I used Kira ALL the time till I got Doc.
I'm Watchman spec.
I never died on any class boss, not even once (I interrupted).
Oh also PvP is a joy to play, specially when you're going 1v1 - Sentinel pretty much unbeatable in that department (well maybe by Operative or Scoundrel).
The only thing that really bothers me is ability delay/stuttering/cancellation (and defensive skills not going off when I press them). This is incredibly hurting when you're PvPing.