I have used these in a bunch of different conditions and overall say they are a great investment for hiking.
Winter - Surprisingly warm despite the mesh. I wouldn't want to hike directly through snow for an extended amount of time, but on snowshoes these were perfect. I even stomped through some ice crossing a creek where my boot fully submerged and my socks did not get a drop of moisture on them.
Summer - Breathable mesh is great to keep your feet from sweating too much.
Overall, I really like the ankle and foot support. They are comfy right out of the box and I have yet to get a blister. For being taller ankle boots, they are surprisingly light. The grip is also unbelievable - so much better than my previous Keen boots - thanks to the Vibram sole. I would say a perfect boot for fall/winter/spring hiking in rougher conditions but might be a little overkill for summer.