It's a hotel room at the MGM Signature- worked well for me as I had a show at the convention center and hate staying in casinos. You're connected to the MGM Grand via a long walkway, but the property on this side is quieter and less filled with typical Vegas tourist yahoos.

Only difference compared to booking a room direct is you don't get daily housekeeping (fine with me), don't pay a resort fee, and the front desk won't give you a free toothbrush if you forgot yours! They also run a card for incidentals at check in. Good wifi.