I have been using Garmont Radiums since they came out, and still love them. While they aren’t the stiffest boots out there, they are still fairly beefy. They have a really nice flex that is hard to find in an AT boot, and tour great as well. These days I use other boots in my quiver for big tours and ski mountaineering, and the Radiums for driving big skis or on days when I don’t mind a bit of extra weight and want to have fun skiing in a no-compromise alpine style.
Several years ago I tried the 27.5 Radium (my normal AT boot size), but it was quickly apparent that they would be too small. The toe area of the Radiums tapered sharply in, and the end was quite small, making for a strange fit. I ended up going with size 28, a shell size bigger. The size 28 worked fine, except for the fact that they had a sole length of 325mm, while most other boots I’ve owned have been around 310mm. For example, my current favorite lighter weight touring boots are 308mm. This was quite a hassle when switching between boots. The longer sole length also made for a slightly less efficient stride — very noticeable when walking without skis, but with skis on as well.
Apparently quite a few people didn’t like the fit of the Radium, so Garmont decided to change it. I was excited to try on a new pair of 27.5s. I got a pair, and voila, they fit! They widened and increased the height of the toe box, which makes for a much more comfy fit. The sole length of the 27.5 is 315, which makes switching between them and my other boots much easier, and makes for a little more efficient stride. Unfortunately Garmont didn’t change anything about look of boots with the new sizing, so do a little research on which ones you are buying before swiping the card.