I stayed at Bally's from Sept. 20th - 23rd. I used the check-in at McCarran International Airport - this is highly recommended as others have mentioned. I had requested a King sized bed, but as I had arrived early (11:00am) they only had a double queen bed available. I had no problem with this. My room was in the South Tower, and as a previous advisor mentioned, you seem to have a choice between the older rooms in the South Tower with better views, or a better/refurbished room in the North Tower with perhaps not-as-nice views..
Opening my drapes I was staring straight at the Eiffel tower of the Paris Hotel, and was also able to see much of the fountain show at the Bellagio. The room itself seemed comparable to one I had stayed in months earlier at Treasure Island - Nothing too fancy but nice enough for me. I had no problems with housekeeping during my stay. Towels were replaced..all that good stuff. Some other thoughts:
-The Monorail seems to be in a permanent state of broken. Who sold Vegas this thing, Lyle Lanley? (I'm a Simson's fan)
-The lower level where the Sports Book, Pool, Spa are located seems a bit desolate. It doesn't seem like it is part of the hotel....
-The ability to access the Paris hotel is a definate plus. It's lovely and I preferred their casino to Bally's - but it's proximity means that you really have 2 hotels in one.
So summing up, I enjoyed my stay at Bally's. The room rate ($79 per night), location, and general amenities make it a place I'll come back to on future trips to Las Vegas.