I just got one. Your instincts are right about how impossible cool it is. Dave, I'm gonna need you to be a good lad and reserve me one of those elephant pocket squares in the back. For my part, I'll stop drooling and try to get some work done so that I can pay you for it .
I have boots on both the rain and the forest in UK 9 and I find the fit pretty similar. I have more room in the toe box with the forest, but otherwise, both boots fit the same from the heel to the forefoot.