I am a bit intrigued on the hull of the Naish 10ft 10. I can see how this will greatly help with tracking so it will mean good straight line paddling......but does it make it much faster than a similar sized SUP? And do those channels have a negative effect on surfing?

Yes it's pretty quick for a surf nosed board and you can get a number of strokes each side before changing.
Quite a flat nose rocker and the channels will resist turning on a wave quite a bit. It will catch the tiniest of waves though.

I used to have custom channel boards shaped for places like jakes 25 years ago. Channels made the board faster for sure, but you certainly struggled to throw the board around. On big fast hollow waves, channeled bottoms were straight down the line screamers. We had them shaped with less rocker because the aim was for maximum down the line speed. Im not sure why youd put channels in a wide nosed 10.10 sup. to offset its lack of turning youd have to put a banana shaped bend in the rocker outline to make it turn. At that stage youd negate your rocker bottom seed advantage. Maybe its to aid paddling, cos i cant see too many 10.10 sups racing the pit.