I've been thoroughly enjoying the new system. Choosing what you want to work on, and getting paired with actually interesting puzzles has been perfect. I particularly enjoyed the Zugzwang theme.
I tried the interference section and I believe it was programmed incorrectly. To me, interference means the player to move puts a piece between two opponent pieces, interfering with the opponent's defense.
lichess.org/study/YtBYXc3m/yrtbspB1 is an excellent example of an interference move winning the game. However, lichess is currently programmed so that in a puzzle, via a sequence of forcing moves, forcing your opponent's king to a certain square that "interferes" with another piece defending a third piece qualifies. To me that's not interference. Maybe more of a "remove the defender" type of puzzle. Anyway, beyond that one definition difference, I've thoroughly enjoyed them!
Also, unfortunately, the new system sort of invalidates your puzzle rating for good now. When I'm bored, I'll crush through 50 smothered mate puzzles in a minute. Pretty easy to solve them in a second when you know they're smothered mates. The fact that this affects my puzzle rating doesn't quite make sense to me, but it's all good - puzzle rating never meant anything before anyway.