2007 Mazda CX-9 Navigation System?

[Navit J]

I have a few questions to ask, I have searched all of google, and some people say that the navigation system you in the CX-9 isn't that good. Has anyone else had a bad experience with it? Is it voice activated so you can talk to it? What model is the gps system? Pros and Cons? Is the rear back up camera useful, and is bluetooth good? Please help me out I have been interested in buying this vehicle (used one of course) for quite some time, and just need some last minute thoughts. Thank you,