Ok guys after a near hernia trying to move this big box downstairs, some first impressions.
It is definitly smoother than the PB12-NSD, yet still has that elusive punch the Axiom subs seem to lack, other than that I need more time and the direct comparison with the 600. The PB13 also has a magnetic grill so it has that cool factor to it.
I listened to The Eagles Farewell Tour DVD - Dirty Laundry. The bass was not over the top but still had a nice edge to it and the depth charge scene from U-571 had the pant legs moving and there was a definite visceral punch on some of the explosions.
This sub has lots of adjustable settings which is why I need more time, lots more time as the schedule is getting filled with outdoor activities. I will guess that with the onboard EQ settings just about anyone can get this sub to sound good in any room.