I thought the ray was just after the fish I'd speared, but when I got out onto a rock I left the fish on the float line in the water and the ray didn't try and eat the fish then. It came right up to me when I was on the rock too. Starting to think it was just messing with me haha.

Not going to lie I pood myself a bit

My mate uses one on occasion . A Beuchat Marlin Revolution. I wouldn't put my hand in front of it if it was loaded. I have seen him shoot kingfish and snapper with it. 

Thanks for the replies. Dont see too many for sale in NZ so was wondering if they are as good as some people advocate. Would be great to hear from someone that does use a roller.

I wonder how much accuracy is affected by recoil, in particular by the barrel rotating about the fulcrum (handle). You could make a delayed recoil speargun based on the roller design by flinging mass back towards the handle as the spear was accelerated. Still need to deal with slowing that mass down again, but you could postpone barrel movement it 'till the spear had left. Just saying.

I've set a 120 Rob Allen up as a roller. 

check this company – they're kind of affordable too:
http://mvd.gr/index.php/en/underwater-fishing/roller-heads/spear-head-roller-detail

I stole the idea off you and made a FB BOP spearfishing page. https://www.facebook.com/bopspearfishing

As a noob of 30 odd years spearfishing (like the guitar, its a hobby keep picking up and dropping) Im always confused as to how to know what suits to use in what temps.

I wondering if I can get away with a 5mm with 7mm vest in welli during winter, up to 2 hours.

i feel the cold in a 5mm in spring in auck :-)

I use 5mm all winter long down in Welly and could happily stay in the water all day. New suit though and maybe I don't spend as long lurking stationary at depth as some which must help.