I love Spa Mio. We stayed at the M Resort a few weeks ago and enjoyed a heavenly spa day. The staff was fantastic. From the front desk staff who remembered us from the previous day and called us by name, to the spa attendants who were bubbly, informative, and present but not overbearing.
I really enjoyed the spa facility which was clean, intimate, and beautiful. It is smaller than your monster resort spas on the strip, but I prefer that. Everything was easy to find, they had good amenities, etc.
My massage was very relaxing and my manicure was great as well, but my favorite part was the facility.