Hi -
When we had to move Mom from the ALF, I looked into just two of these homes in our area. I found them on-line and in the phone book, and just dropped in. They had no time to make things look good. At the first, there were about 25 residents. The yard was surrounded by an 8' chain link fence and there was a resident lying in the grass with no staff member in sight. Several of the more disabled residents in wheelchairs were slumped and dressed only in diapers and a shirt. I could tell at after 5 minutes that I didn't want my mother there.
The 2nd one was much more like you describe, a few residents and a very nice setting. I decided that my mother was too far gone at that point to benefit from that type facility. She was no longer very sociable.
I imagine that your local counsel on aging or senior resources have records of complaints and such about each facility and perhaps there is an accrediting agency you can check with. I'd also suggest you drop in on the places you are considering. That will tell you a lot. You can ask about recommendations when you visit, too.
Good luck! Barbara