5 star trail running shoe. I've just completed my 3rd ultra with one pair of cloudventures and it is just as comfortable as out of the box. They have handled really nasty, gnarly trails and I find they keep really good traction (dirt, rock, road) and drain really quickly going through water or mud. I find the shoe tends to loosen a bit near the end of a long run, but I should have stepped down a half size.
Uphill climbs are nice because of the traction you get, and downhills are also comfortable due to the design of the shoe as it handles downhill pressure. I find my knees are still in really good shape after long runs (30k+). The toe guard saved me numerous times over technical trail runs, and I found the overall build of the shoe can handle anything.
Even slogging through mud, I find it can get stuck inside the cloudtec pods, however after a few steps, the mud completely shakes off, and drainage is no problem.
Highly recommend the cloudventure.