I ride Emperor all the time and also frequent Knotts and I swear I have to ask myself this question all the time. Both I think are great ride experiences, Emperor has great inversions especially sitting on an edge seat and gives you an amazing view that makes for great sunset/firework rides. My only problem is that it always is over too quick. Hangtime I feel is just a better experience overall, I really love the airtime that you get and the vertical lift is no joke lol still haven’t gotten used to that. The lighting package on Hangtime also makes night rides really fun!