Personally I dont quite understand how it eats the clutch, however it can interfere in normal driving conditions if you know how to drive. It's a safety measure designed to prevent accidents in slippery conditions or for those who dont know what to do if a car starts to slip. However, when racing or when you know how to handle your car, it can interfere quite a bit reducing acceleration times and screwing up cornering.
Personally, I drive with it off all the time unless it's pouring outside. This is why I made that auto-vdc off kit (which i'll start offering sometime next week for those who are interested).