Nextdoor is a great concept. It unifies neighboring communities. I have gotten great references (some not so great) on many workmen, etc. It's good to know what's going on in the neighborhood, sometimes on an hourly basis, when you're at work. Alerts us to suspicious persons in the neighborhood.
Sometimes some people get into little spats and can get rather nasty. I wish there was a way to curb that behavior. Also, I'm not crazy about the new format. I liked the old one better. It was easier to skim through.