I love living in a neighborhood that is mostly older people. This is not due to being an over 55 community, but due to the natural demographics of our neighborhood. Most of our neighbors are in their late 70's, 80's, or older because most of the homes have not been sold since they were first built around 1965. When one of the owners dies or goes off to a CCRC, either their children (in their 50's or 60's) move in, or else they sell it to someone who is usually older too, like me.
One of the advantages to living around older people, is that it makes me feel young by comparison.
Also I like older people and their values, they don't have wild parties, and they have gardeners who mow regularly so their front yards look well kept up. I don't need to tell them to get off my lawn because they aren't on it. They mind their own business.
When I see a woman with a walker going up and down the sidewalk in front of her house, it makes me want to cheer! She's doing her best to fight back Father Time and get healthier. And let's face it, older guys often use canes just because they are attractive, good for self defense, and make them seem interesting, not because they are totally necessary. If I see an old guy or woman with a walker or cane, I think about the stories about old New Orleans that he or she could tell if I could get them talking! They are priceless assets to our community.
By avoiding over-55 neighborhoods, I think one is excluding what could probably be some of the very best, most peaceful neighborhoods around.