Coach, I have very wide feet (270mm x 115mm; EEEE) and the 305's were recommended by a respected boot fitter for a racing fit with lots of mods (mostly grinding) for my 6th toe. I picked up the 315's for the buckles (I catch them and bend them on b-net [while coaching] and stumps), but when I put them on, with my 305's liners, I had found my new free ski boot. No adjustments needed. An all day fit. I'd say they are pretty voluminous.