[sunfish]

My feet are size 10 (British size 10). The fireblades pockets say 44-46 10-11.5 .
The beauchat pockets say 45-46 11-12 .
The beauchats are noticeably bigger but feel only a little bigger on the feet. I wear a 3ml sock with both.The beauchats can take a 5ml sock. I haven't tried a 5ml with the fireblades, but suspect I could squeeze one in.
I've only tried the fireblades once so far, so although I'm impressed with them so far, don't read too much into my review 'til I've given more testing.