Hey Surfrod, I tried it for the first time today in the roar comp but conditions were pretty terrible for me to give a proper review. It's definitely more stable than the Naish 8'10" and turns well but didn't feel quite as loose - but this could have had a lot to do with today's conditions.
Will post a better comparison when i get the board into some proper waves.

Well I got the chance over the weekend to try out my new PSH 8'6" WR is some clean 2-3ft waves at Greenmount and this board really rips!!!

Very stable to paddle out on (I'm about 80kg) and relatively easy to pull through the whitewater in 2-3ft surf. Paddling for a wave I found I could put more power into my strokes without loosing stability when i'm pulling hard to get on a wave (I'm comparing it mainly to the Naish 8'10" as that is what i've been surfing for the last 8 months and have really enjoyed).

Where this board really impressed me though, was once I got onto a wave - I was expecting it to be slightly harder to manoeuvre because of the extra width - but I was wrong. When you step back on the tail this board really comes alive and turns quickly, tightly and with ease. It didn't feel like I was surfing a board that's 30" wide, but the extra stability meant I could pull myself back from couple of turns where I thought I was gone for sure. (For those of you interested in the fin set-ups i've only tried it with the standard thruster set-up it came with, but would like to try it our as a quad sometime soon).

I haven't put it into some real juice yet, but from the way it felt I think the board will handle it fine (its just a question of whether I can live up to the board in the big stuff).

This board is AWESOME!!! and I'm stoked to have gotten one before the first shipment ran out.