I just bought these shoes last week right before my first Tough Mudder in Maryland. I know not the smartest to use shoes never worn, but I have had a lot of confidence in Salomon's in the past. First time wearing them was the Tough Mudder, they were awesome. It was raining during the event and it was so sloppy they actually cancelled the race on Sunday. I had no issues at all. I wore Darn Tough lite hiking socks. My feet felt great. Lots of others were slipping around and I felt like my feet were glued to the ground (mud).  They even cleaned up really well after the race. Just wanted to throw out some input. I look forward to doing some normal trail running in these as well.
Good Luck and the Enjoy the Challenge!!