I found the EDL a complete waste of time, allegedly it's supposed to crudely emulate a diff lock when you get wheelspin below a certain speed by braking the offending wheel, but it never seemed to make any improvement in snow.
(What you really need is a set of winter tyres, conveniently I have a set for sale, see my sig
)
The ESP system incorporates all of the ABS, EDL, TCS functions, with the addition of various additional sensors (lateral acceleration, yaw, steering input) and software.
On the Passat it also beeps away at you when it's activated, as if to say "stop driving like a tw@t", which I find quite annoying....
Ed - didn't you say the other day you's slap anyone who suggested you didn't use the throttle like an on/off switch