According to our information it is the updated version.

Unfortunately I don't have a suitable scale, but yes, the headset does feel so light.

Possible, yes. However, only if you have an aux connection on your mobile phone and you cannot use the universal connection (small screen with sound wheel). It works with a jack plug.

The "X" model is designed for Xbox consoles and has a dedicated Xbox port. It still works with other consoles and PC though, but if you have a Xbox, the "X" version is the one to choose.