Mandarin Oriental hotels are known to have great spas (in fact their hotel-spa in NYC is ranked as one of the best in the world) and this one lives up to that reputation.
However, my experience with this spa is limited as the exorbitant prices kept me away from trying too many of their services/facilities.
The concierge desk service was very helpful and polite - and accommodating. I had a $100 spa credit and was flying back that afternoon (on a Saturday). They did their best to fit me in somewhere and give me a taste of their spa treatments. The one I did was the 25mnt foot treatment.
The room overlooked the strip (from the 7th floor) and it was a beautiful view. The massage therapist was very sweet and knew when I wanted to chat and when I just wanted to close my eyes and relax. Their products were great (smell and feel).
The foot treatment itself didn't seem as great to me because it wasn't really a massage (more a cleansing/lotioning treatment). And it cost $90! Which I totally didn't think was worth it (even at a Mandarin Oriental Spa).
Finally, there was some lady at a not-so-nearby room talking way too loudly to be ignored, which broke my sense of serenity.
I do hear great things about their showers and water treatments and wish I had tried those instead! Just a fair warning on prices though - their couples massage costs anywhere from $450 to $800 and most other massage treatments start at the $250 price label.
P.S. Highly recommend booking a treatment days in advance as they do seem to be very busy!