Love it. I stay here every time.
I've been to Vegas on several occasions and always stay at the MGM Grand. Even the Grand Tower rooms are very nice, but if I'm with my wife we always opt for the Celebrity Spa Suite.
It seems that quite a few of the bad reviews come from people staying in the West Wing rooms. I have never stayed in one, and do not plan to after reading many bad reviews. It's a shame that the West Wing gives so many first time MGM'ers a very bad taste in their mouths. I was in Vegas for the CES show in January and was offered a complimentary upgrade to a West Wing room (i was flying solo for this trip, and stayed in the basic Grand Tower room for this trip), and refused the upgrade.
One other bad thing is that I've somehow managed to get the same front desk lady multiple times spanning over a few years. I never remember her until I'm already there. She is NOT a very helpful person to deal with. Very sarcastic sounding and snotty. When I check in this Sunday, I will definitely steer away from her line! The rest of the staff though has always been nothing but friendly!
Now for the good stuff. The beds in all rooms are A-MAZ-ING! SO comfortable. My rooms have always been very clean and well kept. It seems like some of them have been redone since I started going there around 2005. I really like the Hollywood theme in the rooms, and the bright colored couches and chairs. Very old movie star-ish. The only bad thing I found about the room was that the walls seemed very, very thin. I could hear the guy in the adjoining room talking on his cell phone from my bed. It goes away when you have the TV on, but if you are trying to sleep and have party animals next door, it may bother you. The same thing goes with the hallway. I could hear everyone coming and going, and their conversations, while they were outside my room.
In my Grand Tower room in January, the bathroom had extremely good water pressure, and a nice, pressure adjustable shower head to go along with it. The tub has a perfectly sloped back so it makes laying down comfortable if you choose to do so (which i always do after walking all day in Vegas).
The Celebrity Spa Suite is nothing short of amazing. Its the perfect size to NOT make you feel like you are stuck in a hotel room. I always end up using the couch and living area even though I always tell myself ahead of time that I wont, and that i'd just lay on the bed. But I like to lay on the couch and watch TV in the room, again, so it doesnt just have the feel of being in a hotel room. It feels more like a very nice studio apartment. The bathroom is massive! The tub easily fits two, but could probably hold 3-4 comfortably!
The rest of the Hotel/Casino in my opinion is layed out very nice. The elevators are right off of the lobby so you dont have to walk through the entire casino to get to them. there is a small convenience store thing between the elevator lobby and the desk just in case you need to pick up something on the way to your room.
One tip for people wanting to stay at MGM. Get on their E-Mail promotions list. I'm arriving next week and getting a Celebrity Spa Suite for $95 a night through these promotions. Regular rooms were going for around $60 or so. They are always throwing in great inclusions with each promotion too!
Overall I love MGM, it has its minor flaws, but none that are absolutely deal breaking for me. Great rooms at great rates. Plus, the easiest access to the monorail on the entire strip.
I would just say to avoid the West Wing room if you can avoid it. It seems they are the ones that bring down MGM's overall review rating, which is pretty sad.