I did a lot of research prior to buying this boot. Unfortunately, there are no retailers in Arizona, so I was unable to actually try on the boot ahead of time. I ordered both a size 12 and 13 (really wish they made a 12.5). The 13 felt much better so I returned the 12.
These boots took about 4 or 5 short hikes to really break in, but now I don't even need to wear socks (but I still do). I bought these because I blew out my old boots while training for a Rainier summit attempt, and wanted something that would stand up to the rock hard conditions of training with a heavy pack.
The Alp Trainer has done just that. There is little to no heal slip, and the ankle support is fantastic. I have rolled my ankle several times on loose rocks with a 60 pound pack without injury.
These boots are truely comfortable with the integrated tongue design, and the different options to lace.
I would not hesitate to buy another set if these ever get worn down (no signs of doing so after 2 months of training 2-3 times/week).