I noticed this too, in BC it was 100% fine, in WotLK it was 100% broken, but now it's really not a big deal. The only class that has a hard time getting back up is a Death Knight, but they have Death Grip so it pretty much evens out. Honestly I don't see Z Axis maps being that broken right now, although I will say I hate Dalaran because the boxes have the most bizarre LoS of all time.