While any information is better than none, when it comes time to actually make a decision, I believe that nothing takes the place of an extended term of visiting, observing, and then talking to the relatives who have a family member living there. No amount of study or review can take the place of actually being there.
DW was an activities director of a mid size nursing home, and was there tho see everything, every day. The most feared visit was that of a state employee, who would review the home for deficiencies. The list of checks is almost endless, but in the end the report is based on observed violations. Fair enough... but... not the final word.
After going to one of the sites linked here, I was surprised to find that the nursing home in my CCRC, while rated five star overall, had one low mark, re patient safety. Curious, I went to the actual written complaint to see what the problem might have been. It was a five page, single spaced report of a single incident that the "rater" had seen. It happened at lunch when one resident was observed "pinching " another. The review listed in detail who pinched who, and detailed the back and forth between R21 and R21, and the aide who resolved the problem. Yes... 5 pages. The complaint came from the fact that the aide did not file a detailed report of the incident... which resulted in the low grade. That was the one and only observation re: patient safety, and the problem was not that the incident was allowed to occur, but that the proper report had not been filed.
I did not pick and choose this report... and there were no other indications of safety considerations. Mentioned to suggest that sometime bureaucracy can be blind.
One more thing to note... not all websites that purport to list the facilities in a given zip code are accurate. One of the most popular, that is advertised on TV, only lists those facilities who have paid to advertise on the site.