I like the Roulette as is. On my BRD (level 48) if I get a lower level dungeon.. say Copperbell, my exp per mob is only about 777. However, the bonus exp at the end is gigantic (I've see around 250k). On the other hand, getting a dungeon more my level range, the mobs were netting almost 3k each, but the completion bonus was only about 80k. I'd say they have it right. I am absolutely in love with this part of the patch.