I have stayed at Bally's numerous times, and have always been treated like a valued guest. Even when they mess up (which isn't often) they more than make up for it.
On our honeymoon, my wife and I got upgraded to a suite at no extra cost and without asking. The one time they messed up our reservation, they put us up at the Flamingo on their tab, and when it was straightened out, you would have thought we had just announced we had just bought the place. We got com-ped at the Buffett every night, and got free show tickets as well.
Whenever we go to Vegas, we stay at Bally's, and plan on doing so again.