I got this for in-air use with my computer/tv combo. Setup is straightforward and it comes with a neat charging dock, which works nicely. The mouse does everything you'd expect it to - it's a nice touch that it can be used in-air and on a desk. The desk mode is optical, and works fine on every surface I've used it on so far.
Range is good enough for my flat - I haven't run out of range yet.
In-Air mode is flawed. You have to pull a trigger in order to tell the mouse to move. I understand why this is done, but it makes moving and clicking quite difficult. They should probably have made the buttons easier to click also. Additionally, there are programmable buttons on the top of the mouse, which seem to come unprogrammed, and with no instructions explaining how to do so.
It works, and will probably work for presentations, etc, but it could be better.