I would most certainly size up half a size. In my case it fits very poorly and are my only disappointment in an AE shoe\boot. It is no longer on the AE website but a customer had posted pictures of his in greyscale with what looks a 20 ga. AyA SxS shotgun. Even though I prefer my pipes to be stacked O\U I found it hard to resist purchasing the Yuma as I shoot a lot of shotgun sports and bird hunt most of the fall. His also looked to be the Nordstrom edition which is a solid color instead of the 2 tone AE version:
The reviews for it on the AE website are favorable for the most part. I found it fit me very strange and has very little support, I don't believe it has a shank at all. Soles are thin and you can feel rocks under your foot. It isn't quite a stalking boot but close. I purchased mine in 10D which is my standard size in #1 and #5 last with the exception of the waxy leather where I drop down to 9.5D. I will eventually sell mine and state that they are best suited for someone with a 9.5D or C foot. I own LL Bean bison chukkas and BB bison boots and put them both above the Yuma, but could have just been a bum pair of Yuma's that I ended up with. I have been using my AE Bayfield boots quite a bit for sporting clays and skeet and really like them for cooler and wet weather. For the last 6 weeks or so I have been shooting 2-3 times a week wearing my AE Kamai's and have really come to appreciate them a lot, head and shoulders above the Yuma. For actual bird hunting where walking 6-12 miles a day is the norm I wear boots intended for that, and will continue to do so.