I have created a site at Grou.ps
and I must tel you that I am pretty satisified with what they have to offer. This site is specially good for people who cannot afford to get the features like as present in NING.
There are certain features which caught my eyes
1) Have lot of inbuild theme.
2) Your updates are commentable and likeable as it is in facebook.
3) You have online members tool, Latest members, top contributors, blogs, videos, photos and cool games as well.
I have a premium ning site
, but I still wanted to make sure that I could be of some help for people who would want an alternative solution next to ning.
I would personally recommend to go for Grou.ps
than to Spruz.
I created a site with spruz but I am not quite comfortable with it though, well everyone has their own opinion.
Hope this helps.