Had it on an E46 M3 was a pain in the ass it always lowered too far so you couldn't see the curb over the back wheel made it a bit pointless. But never tried changing it.
On my other car it is linked to the seat memory, so dips to the right place for the driver. It's one of those simple, but brilliantly effective things and if it saves me a graunched alloy it was worth it
Hunter, do you have an Intravee fitted? Reading their manual it looks like it offers some additional features including some mirror related, and also showing the PDC on the screen? I'm thinking I might just buy one anyway now...