I was in Las Vegas with friends, some my friends stayed in the actual MGM Grand resort, and I do feel staying in the Signature was a much better experience. Cheaper, cleaner rooms, more responsive/ less crowded concierge, easier to catch taxis/Lyfts/Ubers. Walking to and from the MGM was easy and took maybe 10 minutes to hit the middle of the casino floor. You're very close to Wet Republic or Hakkasan if you're planning to hit those spots, and it's an easy walk to the rest of the strip. Room overlooks part of the strip and the Tower 3 pool - it was wonderful to look out over even in 104 degree heat. Check in was a breeze, but do know that they will need to put down a credit card for security purposes (which is not necessarily the case for all AirBnBs). We didn't end up needing much from Mia, but her check-in and introductory instructions were more than ample for the whole weekend. I ended up needing to take a work call on the trip, and there is a nice roomy desk available in the room if you find you have work to take care of while staying there. Bathroom is huge, with a great shower and big jacuzzi tub.
All in all, we didn't spend a ton of time in the room, but for the price, this was absolutely more than we could've asked for and was a luxurious place to rest.