I'm afraid I can confirm most of what has been said above about what care homes say they will do versus the reality for residents.
Just visiting a formerly active and spirited relative in two homes chosen by others (with best intentions and doing the kind of checks necessary), I found that bringing problems to the attention of the staff was sometimes met with resentment, bordering on insolence. Latterly, I often left in tears. I did try to raise my concerns with the responsible relatives and the home management, the former having more effect usually.
Admittedly, the cared-for person became increasingly difficult through dementia, but was much better when stimulated (better in the first home), most of which (in the second home) was left to us visitors who were very restricted in when we could visit, by a rather devious system which made us unwelcome in the main visiting room for an hour before every meal and some time afterwards, and an early afternoon staff meeting IN that, leaving about an hour for a visit before the room had to be cleared again. I often - through work - passed the home at times when I could have popped in to say hello to a very lonely and isolated friend, but it became impossible and my visits dried up.
There's lots more but if you ask the closer relatives they will tell you it was a great home and the care was OK. I have no children (just a step family) and it has made me think very carefully about who should have the say for me, though needless to say I absolutely dread the thought of ever going in to a home.
What I would say is - even if you think you have a great choice for your loved one - visit often at different times, ask questions and notice things.... like: - How do the staff respond to requests for the toilet? Do you ever see immobile older people "parked" alone facing a wall? Do the residents, especially your loved one, ever get out to feel the sun on their faces in those beautiful grounds? How long is it before the doorbell to the locked home is answered, even if you can see people scurrying back and forth?
I read the reports on the homes and was pretty shocked to see that the questionnaires for relatives were given out by the manager. Needless to say I never got one. Even if I did, I had no proof of my observations and would have worried about the effect on the resident.
And to that, I must add that there are some really good people working in all homes. Kind, intelligent, honest people, but they have to go with whatever the rest of the shift do and their lives are hard enough in what is admittedly a difficult area. Sadly, I think my very limited experience of private care homes ranged from good-at-times to bad to very ugly, but in a local situation the staff might be your neighbours, children of friends etc. This, too, can make challenging the system very difficult.
On the other hand I do know - and have experience of visiting - a local authority home which is a lovely environment for older people. The waiting list is a mile long.
In Scotland, there has been a lot of controversy about the new Named Person scheme which gives children an independent state-appointed adult to promote their welfare. There is a crying need for such a scheme for the most vulnerable older people in care homes.