Get your walkin' shoes on - this place is HUGE! I stayed in the Grand Tower for five days for a conference. By the fifth day, I just started to figure out where everything was. Staff is very friendly, knowledgeable and willing to help in any way. There are a tremendous number of restaurants - upscale, casual, and everything in between - and shopping available inside. Do be aware that the main lobby does not front on the Strip so it is a long walk through the casino to get to the Strip.
Rooms were comfortable and well stocked. I particularly liked the electric blackout curtains to help me after a few long nights.
The MGM Grand is not the best hotel I have ever stayed at, but it is very good at what it does. If I come back to Vegas, I would certainly stay here again, but I will be willing to check rates at other properties on the Strip and check to see if I can get a better deal somewhere else.
Special tip - go to the Starbucks at the west lobby in the morning. The lines are much shorter than the lines at the other two Starbucks (yes - there are three Starbucks. I told ya this place is huge)