I am 9.5D US on the brannock. I went with 8.5Uk for the button boots on the 363 last. They are a snug fit. I do not find them loose at all. The suede follows the top of my foot pretty well and the heel cups the back of my foot well. I do not think i will have any issues once they are fully broken in.
Thank you bud so I did pick a right choice I just went down one full size mto button boots from my AE 5 last size 10 US to 9 UK could also fit 9.5 AE US it was very super snug fit, size 10 was very comfortable so I am hoping 9 UK would work & is good fit.