IF (big If) I get my rods upgraded then I will start banging up the boost and timing to see just how much can be had out of a K04, then I will purchase WMI. At the moment I've run out of jobs to do on the car so it's just maintenance and cleaning
Cooler engine = happier engine.... Cleaner engine = happier engine.... Higher octane = better and more efficient burn.
It's not all about the timing advance, you WILL benefit much more from this than a intercooler purge system, and it's not really any extra hassle. You will still have to fill a tank either way.