I've been wearing Salomon Speedcross for about a year. I swore I'd never wear anything else, but hiking on the Appalachian Trail in Pennsylvania, suffering a bad sprain and a pretty messed up toe, I decided to look for something that offered a bit more protection for those rocks but did not want to switch back to boots. The description on the TNF Ultra Endurance made me want to give these a try.
The verdict... These are awesome! There was no break-in period. They were comfortable right out of the box. I experienced zero hot spots or blisters. I normally wear a size 7 but in the past have been a 7.5 in TNF... in these a size 7 fit perfectly.
First day in them I logged just under 9mi over rocky AT Pennsylvania terrain. Day 2 was just over 17mi.
The grip on these things was phenomenal. There's a section called Knife Edge where big boulders slant at an angle and yup, you gotta walk across them, feet slanting. I always felt completely stable on my feet. Bear Rocks was a climb up big boulders with some rock hopping and no falls and secure grip. Even managed to keep grip on a narrow rock for tree pose!
All in all, I think these may be new go-to trail runners
UPDATE: I've put about 200 mi on these, mostly on the AT in Pennsylvania and for anyone who knows, it's more like ROCKSYLVANIA! These are holding up incredibly well. Good tread and cushion remain. On a 22+mi day in PA, I had no pain at the bottom of feet despite all the rocks. "nuff said!