For me this component is one of the best components I have used so far. If you are creating a community website then JomSocial is the way to go. It basically covers all basics a community component should have; status updates, photo and video uploads, groups, events, like/dislike, activity stream.
The component makes the members (350+) of my website www.testdriveunlimited.nl come back daily, making new friends, discuss topics in the groups of which they are a member, upload photos and videos. Without JomSocial my community would not have been this active. For me this shows the power of JomSocial.
Yes, the support is not always that great but in general I get my questions answered. The team of moderators is getting bigger and lately I see that support is slightly improving.
Hopefully the development team behind JomSocial will now first focus on stability before they will add new functionality. Also a few more default templates would be great. Especially different colours schemes on the existing templates would help a lot of users to have a better integration with their website. I am using a Rockettheme template and there the fonts and font colours within JomSocial are generally being used from the main (Rockettheme) template.
If I can give potential new users of JomSocial one tip, try not to customize the component too much. For me this works great especially when a new update has been launched. If you are an average Joomla user then you should be able to get the component to work as you want it to work. The backend settings are not rocket science but because of the many settings you should take your time to get the best settings for your site. Just go over them one by one and you should be fine. It is all organized in a logical structure.
I am giving this component 4 stars because stability and support can both be better and hopefully 4 stars is stimulating the JomSocial team to make it 5 stars ;).