As the title says i have a hard time deciding between these two properties. I have stayed at Red Rock before and really liked it, i have been to the M but never stayed there. Im looking for a resort type experience trying to rest up a few days after a road trip touring the wine country and Yosemite before moving on to the strip. The spa and the pool is important so comments on that regarding the M will be helpful. I really want to stay there to change things up, but i know what I'm getting at Red Rock plus i guess the new outdoor mall in Summerlin is a nice added bonus from last visit. Any pros and cons that I'm not aware of would be nice from you people who have stayed at both properties. Also we are a group of 4 and have a car so good restaurants close by will also be a plus. This trip will happen in early June if that matters.