Thought eaters: now with actual danger! At least relatively speaking.
The basics: 14 aberration RHD, Huge size, +14 natural armor, and a 3d6 bite. Ability-wise, thought slayers get the expected big boosts to strength and constitution (+16 and +10), with smaller bonuses to everything except intelligence (which is penalized instead).
Their special qualities are a mixed bag. PR 21 is the double-edged sword it's always been, at-will Ethereal Jaunt is still useful but definitely less impressive than it was at ECL 3. Note that in spite of all its added power, the thought slayer still dies if it spends a minute on the material plane, so be aware that a single Dimensional Anchor can kill you (then again, what D&D character doesn't die to the right 4th-level spell?).
The PLAs are neat, but all suffer from being quite low-level and just not all that impressive. At-will Brain Lock would make for an amazing spammable save-or-suck, but sadly the DC of 14 (hard to raise without suffering from MADness) puts a damper on its viability.
Finally, there's the slayer's Mind-Consuming gaze, which could've been interesting and quirky but instead is just another boring save-or-die. Try and not catch your allies in the area, because Narrowed Gaze is hard to get with a -4 intelligence penalty.
Final verdict: the thought slayer has a lot of tricks, but most of them are outdated, hard to use, or just not all that impressive. -0 LA, but I'm open to arguments for +0.