I'm staying at SLS soon. I love the spa at Aria and at Cosmopolitan. Anyone here been to the one at SLS?  
I actually like the room product at SLS.  It's not as refined as the other two I mentioned but the rooms have some fun quirks.  So I'm trying to decide if it's worth it to spend time at the spa there. Thanks for any insight.

SLS is a flop right now.... I could give a lecture on everything wrong with SLS but I'll just suggest stick to Aria or the Cosmo.

I agree that overall aria and Cosmo are better products. But I do like the world tower room setup with the mirrors for a fun night.  It's a nice change of pace even if it's not overly luxurious.