Ballys is one of the older hotels on the strip, but it has been nicely maintained. For an older hotel it's not that bad and reasonable priced in general. However, with that said, if you compare it to the Ventenian or even Mirage, it's not as good in my opinion. The fitness center was actually a little disappointing and the once famous Big Kitchen Buffet wasn't all that great (it used to be spot on for dinner).
One thing going for Ballys is location. It is smack in the middle of the strip which is great. If you truly just need a place to crash, Ballys is a good choice.