I've shot both, they are both decent guns. I own a PMR and they are very easy to maintain and great to use. Very light, very efficient (in the +/- 2-4) and they are great out of the box.
They also have a fairly good upgrade path; Plenty of aftermarket triggers, frames, boards and even detents.
The shocker is also a great gun, I simply havent said as much on them as I dont have much experience with them. But one thing I do know is there are lots of upgrades available due to the fact many teams are using them.
As many people have said, its down to personal preference. But whatever you choose, you shouldnt be dissapointed.
-Will