I am a huge fan of the Mandarin Oriental properties worldwide. I have been to the Las Vegas property several times for cocktails on the 23rd floor and I have some friends who live in the Residences.
The property is always clean, smells lovely and staff is very accommodating. I recently stayed here for a mini stay-cation celebrating a special event and the experience was definitely five stars.
Poolside is lovely. Be sure to order the pineapple mojitos and the hummus plate (ask for vegetables instead of tons of pita bread).