Very comfy from day one, but the top part of boot would get loose after 2 runs. Not good when you foot starts to come out of the boot on a tight curve! I bit to flexi would not call them 8-10 on firmness. Aside from that nice boots, fit great from day one. There was no need to break them in, Burton got the comfort form down.
I was thinking that with how stiff Burton put them as they would be nice for free riding but they seem more suited for the PARK.