How much difference is there in the new North Vegas compared to last year's model?
I am riding 2012 Vegas, they are still in great condition but I have been offered a really good trade in/buy new deal, I kind of don't really need new kites but if there is a noticeable improvement then it might be worthwhile.
Any feedback appreciated

I haven't ridden the new 2013 but from all I've read, it seems the Vegas has changed for the better more than any other kite in their range. Better low end, more stability and has had some IDE from the Neo put into it so is a better freeride kite, more smooth and less jerky. I rated the Vegas in the surf. Only thing is bar pressure is meant to be the same of a little higher and I found it a little high. Not in the pull, but trying to turn the kite.

Sorry that's all I have but others who are riding them will probably comment on specifics. Have you checked the kiteforum or googled reviews their are quite a few around. Great kite.