I have taken this shoe out on a couple of long day hikes so far and it has been everything I've been looking for. It is comfortable enough to hike the long miles on trail but also grippy enough to scramble on rock and snow. So far I have taken it out into the Sierra's on wet granite, trails with lots of sharp rocks, steep soft snow, and steep dry granite. This shoe handled all with ease and definitely gave me more confidence. I had been using the Altra Lone Peak's prior to the La Sportiva's and those fit well but had terrible grip on Granite, especially wet granite, not these-the grip with this shoe is insane!
As for fit- order a full size up at least. I am a 11.5 US and ordered a 46.5. It was a little tight in the beginning but that is to be expected. After 10 miles I don't notice any tightness. The width in the toebox is good after the initial break in period. This shoe is also super light weight. I think I finally found my shoe for long peak bagging days that require a long approach!
Edit: After using this for a season I am editing my review. These shoes were to small and not wide enough after feet swell from long hikes. Order at least 1.5 US sizes up from normal.