5D and mirror lock-up

Is mirror lock-up something you 5D'ers routinely use? Or is the mirror dampened well enough that it really isn't necessary? If used is it true that there is a 2 sec. delay between tripping the shutter and it actually firing....that would be frustrating when trying to time shooting wildflowers with a brief lull in the wind.

I use it regularly though in all honesty I have not done side by side testing. The 2 second delay is only when used with the self timer, otherwise it's one click to lock and another to trip the shutter.

Guy

I figure that it never hurts to use it, so I always try to use it when the subject dictates (and through carelessness, for the occasional flying bird as well).

For landscape, I use it all the time.