Has anyone used Fluenz to learn a new language?

I was originally looking at RosettaStone, but I came across Fluenz and it appeals to me much more because it looks like it teaches grammar much better and the company spends a lot more time on each language lesson than RosettaStone’s mass-production method.

Anyone here have experience with it? It seems like it’s really new, and I can’t find that many reviews for it.