Cheers for the info guys - went for the fox in the end as it seemed to tick the boxes of good venting and good upper spine protection plus some kidney padding which I couldn't get elsewhere - was very impressed with grins alpinestars but the arms would have been a bit tight in my jerseys and they seem hard to get hold of
its a super comfortable on - much close fit than the rockgarden. Slightly less padding but weighs loads less (600g) No idea how well it protects but im sure i will find out soon - for the money £80 its a really good bit of kit - ill test it out this weekend for sure.