If I remember rightly Mind Wrack was slated as a "useless" skill for PvP in the early days of GW, but I've read a recent post, can't remember where, that it's now an "essential" skill if you're running E-denial. Yes it's low energy, and spammable but I have a few issues with it why...unless I'm missing something really obvious it still seems like a load of poop. Please feel free to advise / correct / flame me for my stupidity, but here goes.
1) Mind Wrack only triggers when energy reaches 0, so you can't run it in builds with energy degen as the target would reach 0 and stay there, rendering further Mind Wracks pointless. So presumably you're going to Weary, Burn and Surge the target to get rid of energy, but that's only 30 energy and recharge about 20s for all 3 (if you use Sig first) so you're just standing around doing nothing for a while, and they can heal themselves up.
(Arcane) Echo etc I suppose...but 15 energy for the former makes it too expensive.
30 energy...are you targeting W's and rangers with low energy pool? If so, you'd surely be better running Illusion build with Ineptitude, Clumsiness and some degen, it sees to them pretty quickly if they're stupid and don't realise.
2) Combination with Spirit Shackles? This skill only useful for rangers / W's and the occasional wanding ele but the latter are so easy to deal with it's laughable. Us clever mesmers, necros and monks rarely wand so it's not that valuable IMHO. And even on a W, with only 2 pips of regen, wouldn't their attack rate be so fast as to keep them constantly at 0 energy with Shackles on? ie Mind Wrack would trigger once, then they'd stay at 0 if they carried on attacking, rendering further Wracks useless?
3) For casters you could of course use the incredibly abusive Power Leak for E denial as well, but by the time you've cast Burn / Surge / Wrack / Leak surely you'd be in as bad a state as them? Obviously you could then focus on Energy management but again, it doesn't keep up any damage momentum if you go off and look for something else to do. For this reason, it doesn't seem that strong for casters either.
So why is it an essential skill? Apologies for my demented ramblings, but I'm looking forward to being educated.
S

i'd rather take something like diversion. But i think mesmers generally suck in pvp anyway, unless u can interrupt without migraine effectively.
. Mind wrack offers a way for surgers to identify when they've dropped energy levels. It will also trigger very often against people under energy denial-the extra bonus is nice especially since you're running a character that's very close to util.