Hot spots. Don't buy em! Got em on both of my heels. I walked around on for two days to break them in and they didn't get better!
I decided to try these Minimil boots as I'm into barefoot running to train. So I'm pretty familiar with Vibram products. Let me say, I love training in these boots. They give you some protection compared to being barefoot but also give enough freedom to use your lower leg muscles. First off, they're extremely lightweight which is to be expected. They're pretty durable as I've been training in these for 3 months now with nothing fraying or coming apart.
I should point out that they do feel small but not like when I first got them. I still recommend you buy at least a 1/2 larger.
I wear these everyday for 12 hours plus. I work in an office setting so they're not used heavily. They're comfortable for what they are. My only minor complaint is they have a 2mm heel drop and are not a true minimalist boot which would have no heel drop. I do notice it when I switch to my Five Fingers for running. Until they come out with a zero drop boot, this is my favorite.
I wore these boots in Afghanistan and they served me well. They are unlined and my feet stayed cool in 100 degree plus temperatures. I liked them so much that when I returned stateside, I bought the sage green versions. If you're not rucking several miles everyday, these boots do just fine. They do require some break in time as they do not have a are not heavily cushioned sole so you'll need some time in these to adjust your walking style. Highly recommended though!