They are known to be very good playing cues.
I just picked one up and it plays very good.
I like Jim's taper, I think he knows how to build a great playing cue.
He's interesting to me, as it seems like most people really work fine with him and he does good work. but then there are a couple of people out there that just really hate him for whatever reason. I'd be curious to know what the story is with those people vs. the rest, as it seems he gets pretty overwhelmingly positive reviews besides just a couple of VERY negative ones. There's that one guy on here that hates him so much he has his "bad deal with Jim Pierce" thread linked in his signature. That's some next level grudgery right there.
EDIT: As to how his cues play, they're great in my opinion. I had one of and it was beautiful and stiff-hitting. People love his cues around where I am.