First bad sign here was walking in to the hostess stand. Went here to meet out of town guests who were staying at Caesar's, 18-20 year old hostess did not greet us, when we stated we were here to meet guests, she told us to look around by ourselves to see if they were here - poor first contact with guest and what is supposed to be a higher-end restaurant.
Found our guests ourselves and joined them at the table. Tables were very crowded together and wait staff and other guests continually bumped into our chairs - very annoying.
Design of restaurant was interesting - with glass wall facing the casino floor - casino noise did not infiltrate restaurant.
Had drinks and food at their Sunday brunch - I had an eggs benedict type item, with a blue corn base and crab - lukewarm in temperature and unremarkable in taste/texture. Food of other guests was equally unremarkable.
As this was Sunday brunch, we sat at around noon and visited with our guest until about 1:30-2:00pm (not unreasonable in my opinion for brunch) - they were clearly shutting down for brunch service and setting up for dinner service, we wound up finished out meal while they were turning the restaurant over for dinner. Little regard for remaining guests - noise and activity was very disruptive to our brunch.
Brunch for 4 with drinks was around $225.
Very unremarkable, poor service, poor layout, mediocre food - had much higher (and reasonable) expectations for Mesa Grill.