This is becoming an aerospace video blog. 🙂
The eighties [youtube=http://www.youtube.com/watch?v=ba-dln366-E&feature=player_embedded]
Versus the teens [youtube=http://www.youtube.com/watch?v=gK7ktLXhq88&feature=player_embedded]
Westland Lynx only reached 90 m/s while X2 is doing 130 m/s. The ability to let the rotor spin slowly since only the advancing blade needs to lift in a counter rotating rotor allows the X2 reach a high speed.