Lair is as others said, too long and drawn out. Walk, kill 5 things, walk, walk, walk, kill 5 things, walk walk walk.
Moongrave, while quicker to do, the mechanics of moving the blocks ruins it for me. It just doesn't fit and feels like you are playing a platform puzzle game.
The scenery in Maarselok is nice but the fight with the stranglers is too drawn out on vet, and it seems like such a long dungeon. Moongrave is okay and a fair bit shorter, but the gargoyle boss going invincible at certain health percentages is crap design that only serves to make the boss fight longer than it needs to be. It should be changed to time-based instead of health-based at least. But i'm a fan of blues and purples so I gotta give it to Maarselok.
Haven't done either yet. Was away for awhile but came back and now that I have elsweyr finished, I need to run at least a normal version on both to finish my lunar hall.