This thing originally listed for something like $200, which is ridiculous. At the price I paid-- around $75-- it's worth picking up.
It's got soft (but not mushy) buttons and a smooth neck that makes sliding your hand/fingers around effortless. The strum bar doesn't click loudly like the classic Guitar Hero controllers, but there is some slight aural and tactile feedback, unlike the completely smooth/silent Rock Band guitar strum bar.
And the thing is built like a tank. Solid wood neck, and (I think) an aluminum body. It has the weight and feel of an actual small electric guitar.
It's wireless, with a USB dongle that works for the PS2 and PS3.
I've been using it for a few months now, maybe 10-15 hours per week, and it still works like new. Still using the original set of included AA batteries, too!
If it does end up breaking, though, I'll definitely buy another.
10/10