There are a lot of them in my home town, and whilst I would struggle with lack of space, I can see why people are attracted to them. They are centrally placed, and from what I gather there are communal spaces in the blocks, so people get to know the neighbours, and there is a certain amount of socialising, which prevents loneliness.
We have the McCarthy and Stone ones, and another similar company, which I think is more expensive. There is also an older development which has houses as well as flats for older people. Again, it has a town centre location, and has a warden on site. There is no service charge for these ones, but the warden and garden services etc are paid when the properties are sold. The charge is a percentage of the sales price - not sure what it is, but I think it exceeds 10%. If you live there from say, 55 to 90 years old, that might be a reasonable deal, but if you have to sell after a couple of years it's a big loss. They are popular though, and there is usually a waiting list.
In all cases, if a resident develops dementia they have to leave, which would also put me off. The last thing you need with a diagnosis like that would be to be forced out of your home.
Pros and cons, I suppose. For someone recently widowed, or who has moved to a new area to be near family or something, they offer hassle free move (which may also explain why new ones sell better than older ones) and a good chance to make new friends. For people without heirs, who might not care so much about leaving an inheritance, the costs might be less of an issue, too.
£1000 a month though😳. I didn't realise they were as high as that! What does that cover?