Well Sixty-six is the damn emptiest Trials DLC I've ever seen.
I got done cruising around all of the DLC tracks in 1h20. Feels like a straight robbery.
It's boring, devoid of anything other than "tracks" (the new rider gear is as uninteresting as it gets), and said tracks fail to differentiate themselves from the base game career tracks since they're in a location that's already got several base game tracks on it. The DLC tracks just look like your usual normal career tracks, whereas in past games' DLCs you really could see the difference between base game career tracks and DLC career tracks.
Fusion's DLCs had even less content, but somehow they sparked my interest more.