My two pence.....
I have both LED's and Xenons with cornering function on the new car (2011 C-Class C250 CDI Sport) and have found I do not go racing up behind anyone (I might get stone chips on the front doing that ).
I think it's a bit lame to say all people with LED's go rushing up behind people as it's simply not true. Yes there will be the odd retard who drives constantly at maximum speed but most will be driving carefully not wanting to damage their pride and joy.
You probably just notice the people with LED's more as there are not that many vehicles about with them. That being the case the LEDs are doing the job intended and making the car more noticable. Another reason not to speed as you will be noticed doing it .
The operation of my lights seems to be LED's on the minute you turn the ignition on and the sidelights mounted in the main lights come on also. The Xenons then switch on automatically depending on light available (I have them set on Auto, just like I used to in the K1). The LED's appear to stay on once the Xenons are on.
For anyone thinking about them angel eyes.......Nooooooooooooo your Leon is not a saxo!!!!!