There is a lot to NING I admit to liking...everything Alendar said and the fact that the page design templates are streamlined, but you can still personalize your own page or network. I like the fact that there has been minimal incidence of "server down." I love the fact that NIng doesn't give us grief when we post videos and photos.
I am on a couple of other Ning sites, and they are very good too.
Just curious....what do you like or don't like about NING?