I have the PB10, it's decent, but I really wish I had known what I was getting into when I bought it, I would have gone for the PB12 for sure. I think that an even better bet would be to go for a Cerwin Vega 15". I have a friend who got one for $300 and that thing kicks ass on my tiny PB10.
I just bought the PB10 today. So far I'm pretty happy with it. For music it seems to blend in really well with my Axiom M22s. I've only calibrated by ear because I dont have an SPL meter yet. I tried it out on Fight Club and U-571 and it filled up my fairly large living room with pretty good BASS. I seriously doubt it would be enough bass for a lot of people on this forum I mean my house wasnt shaking. The bass it did produce was very clear and quick and it kept up with all the music I tried with it. The only thing that bothers me about the sub is I'm afraid I'll get the upgrade bug to fast and wish I would have bought something better to begin with. So If you got the money I would buy the PB12.
I was in the same dilemma you are in but decided to go with the PB12. From what I've read, you get deeper bass from the larger subs. I bought mine from JandR for $299 with free shipping. It sounds great!