I think there's a thread somewhere in the FTM section (FTM gear I think) about Pee-cocks. From everything I've read they're pretty awesome, with the only issue being that the harness that comes with it isn't so great. I think the harness is the only downside. Not sure how they fit with other harnesses, but it would be interesting to hear from those that have them. I heard they had some issues with the rod for play being too short or long in some of them, but they've since fixed the problem apparently.
I've been trying to save up for one for so long, I should just bite the bullet and do it, lol.