This is definitely the best extension to build a community. The design is great, mostly easy to customize and the social stream is really cool.
They have basically two support sections: One is official and the other is not "managed" by the team. Sadly they support officially only installing errors. Any customization must be done by yourself. You won't be able to rely on the support - nevertheless, they often help you if they have got the time.
All in all it is worth the money and the 5 stars.
But, they should work on their support!