The Skookum forum on HF is a bit vibration obsessed. Not because SKs are vibration sensitive (they're not - the gyros can apparently function well with up to 30g (30 times gravitational acceleration - a lot) vibes; but the accelerometers do a good job of vibe logging, and there are analysis tools. [They say, with some sense, that a well-built heli won't vibrate much, and the vibes do you no good in the long term.]
Anyway, my X2 was showing horrendous vibes (20+ g), which seems to have been a Scorpion motor, and bad cable routing. Re-routing the cables seems to have got the vibes massively down.