I have have hiked well over a 100 miles in these boots, nearly all off trail. I have hiked trails like Cactus to Clouds in Palm Springs (broke them in on that hike) and climbed up to 5.7 in these in the High Sierras including routes on Mount Darwin, Mt. Humphrey's, Mt. Birch and Lone Pine Peak. On low grade routes, I rarely have to switch into my rock climbing shoes. These are light, sticky on class 3, 4 and 5.easy route. They excel on slabs and class 3 boulder scrambling.As for durability, I think they do very well. I did replace the original laces. They were abraded through at the toe pretty quickly. Not a big deal and expected. The laces going all the way to the toe make for a very nice fit. You can snug them down tight with thin socks for climbing feel and loosen them up and throw on some thick Smartwool socks if its cold out. They are waterproof, so your feet will sweat in them. But nothing unusual for a GTX lined boot. I will buy another pair when these are toast.
"A great concept but poor choice in materials ruins it."
I liked the way these fit but they aren't the boot I was looking for. The sole is a little too soft for the rocky terrain I expected to use them in, you feel every pebble. The biggest problem I had was that the material at the top wore through after only 25 miles, all on trail. I have owned several pairs of LaSportiva boots and climbing shoes and have always had good experiences no matter what I put them through but they missed the mark on this one. I hope they try again.