I am also in the PCP market-I have springers, FWB 124, AA prosport-all 177 and a NP22 for a shed gun. I'm in the suburbs on big lots around 4 1/2 acres and a shoot a lot of starlings, so I don't want my projectiles bothering my neighbors. I also happen to have a couple of scuba tanks (from another hobby). I really like the finish on my AA pro sport and was looking at their S500 or 510 series-comments on them or suggestions. I've also considered the marauder, but sure looks like you end up putting more money into the gun especially if I wanted it regulated.