For those that are on the fence IGN just gave Forza 4 a 9.5 rating with a nice review.
ttp://xbox360.ign.com/articles/119/1198556p1.html
xboxer360 had this to say about the Kinect functionality.
http://www.xboxer360.com/reviews/rev...-motorsport-4/
summary on the kinect points:
kinect-only mode is where the game handles the acceleration and braking and you steer with your arms. it can have 2-player splitscreen mode. you can initiate manual braking in addition to automatic braking if you stick your leg forward
kinect navigation via hand is not good. kinect navigation via voice is awesome. with voice, you can directly jump into any mode or menu at any time without having to press A, A, A, etc. or go thru nested menus. luckily, you don't have to memorize voice commands as they show on the screen.
he preferred the interactivity in Autovista with the Kinect versus the controller. to unlock autovista cars, using the Kinect to complete challenges made unlocking them easier (b/c the Kinect mode is easier to play?)
headtracking was awesome. you can adjust sensitivity as well as manually remove objects behind you that could interfere with the tracking. feels like being in a real car and is especially helping for high speed drifts.