Funny you post this because I recently decided to switch to a Brooks shoe as well for my upcoming Camino and the smaller lugs were my only real concern too.
Yeah, the adrenaline GTS shoes have a better tread. I really like the ones I've been wearing for training so I was happy to find something that was more like a trail runner but had the same basic construction. Super comfortable...
I've walked about 20 miles in them so far. They feel about the same as the regular Adrenaline and Glycerine, but the GTS has a more rugged tread. I walked about 500 miles in my last pair of Adrenalines training for my last Camino, so I'm familiar with them. I tried the Cascadias but they seemed to be a narrower cut around the toes. I have a review I did a few weeks ago on them...the Cascadia GTX. It might have been the Gortex that made them less comfortable than the Adrenalines, but I just thought they were too narrow. The Adrenalines are softer than other trail runners, but I use a stiffer insole that works well.
I wouldn't call them narrow. The Brooks Adrenaline have a lot of room around the toes and the fabric is very soft, so I can't imagine anyone would have any problem with them. The Altras are more foot shaped with a tighter heel but both are comfortable. There is a difference in the feel when you walk. The Altras are a 0-drop shoe, so you can feel that your foot is more parallel to the ground. The Brooks have a slight elevation, but my feeling is that this helps to reduce strain on the achilles tendon...at least I haven't had any issues with it. I don't have the problem with the Altra Olympus, but I did with the Altra Lone Peaks. So I generally suggest shoes that have a thicker heel for people who have that issue.
