I'm using one on my XX, so far, so good, after 50 flights.

However, the mount is a bit on the noisy side, especially if you are using the supplied nose ring. I have just switched to a new nose ring with double rubber sent to me by Alex Lau - rep for X-Treme. I have noticed some difference, but not much.

If you want more info, PM me Jayjay.

Adrian