No! The worst challenge in the game (at least so far) has been the one where you gotta grind one ledge, and then gap to a 2nd ledge like 6 feet away, and then there's another ledge after that setup you have to grind and drop down to the next. I don't know about any of the other modes, but it was physically impossible in HC mode. I had to cheat by running full speed on top of the ledge, throw down landing in 5050 and then ollie out to the next ledge.
Fuck that challenge.