I will stick my neck out here, Doc and others, (you know my memory) I think they used to say something about the ankle fit. Perhaps "some" folks complained they didn't fit "their" ankles - so they took it out. On the other hand perhaps I just heard other users talk about the "great ankle fit". In any case, I will vouch for the ankle fit being the best I've ever had (I have trouble with my feet too), and not only that but they are the ONLY ankle fit boot I've ever had on that you can remove with one hand (no boot jack needed). Also they are the lightest, most comfortable rubber boot to walk in (a lot sometimes) I've ever felt. Next to how I feel about ThermaCell Mosquito Repellers - Muck Boots are my second favorite product of my lifetime, for doing/being all they are cracked up to do/be. I have only heard/read one person say anything about them sliding on his feet, and mine never have on me. If I recall they do say better to go larger than smaller if in doubt when odering. My most usual (shoe/boot) size is 10 but depending on makers/type it can go up to 11, so I ordered what they call a 10-10.5, and I'm good to go. They have ones for colder climates also and I've heard good about them too. I have just the plain, green (olive drab) ones. I can honestly say it would really shock me to read/hear negatives about them. I understand this past year they came out with a snakeproof one too. I hope mine last forever but, if not, I'll look into those - had to "sneak" by a SNAKE just yeasterday in mine - LOL. If/when I go to a real snakey area, I wear my Rocky snake boots (which are also comfortable, and light) but I always miss my Muck Boots when I do, I mean it all.
(Guess this should be in the reviews too, huh? Sorry.)