Today I started playing Myriad Caves. So far I've gotten through the first area with one death, established myself at the monument, and found all of the emeralds in both of those places.
I really like it so far! The first area plays very nicely, and the monument is well done. I can't wait to see what the rest of the map has to offer. I was a bit skeptical at first since I'm not personally a fan of the 1.9 combat (In one sentence, the reason why I don't like it is the fact that they slowed down the player without also slowing down the mobs), but it's not making as much of a difference as I was expecting it to.