Challenge rifts would be awesome if it was someones progression accomplishment rift and we were allowed to use our characters to see if we can match up. That's what I originally envisioned when I heard about these initially. Tier based with greater rewards would give incentive to push. If I could use my character, I would be more enticed to push and figure out how to beat the time. As it is today, I usually try it once and bail if I don't complete it because it's usually a crap build that I don't know or a class I never play. This isn't fun. There is a reason I don't like to play some classes and as designed today I get no enjoyment from a challenge rift when I'm forced to play that class.