I love undercity but the good tributes are a bit too scarce. I want more of the obducite ones, but ive only ever gotten like 8 of them. You can do it so fast, its great. I have some legendary tributes saved up though, which i plan to use this weekend to share with some friends. If it was more rewarding, i would run tons of undercity. I have another 10 or so titan tributes saved up but i dont really care much for boss mats anymore.