I also believe its a good idea that if it isn't broken, leave well alone, mainly as I never have the time to tinker. Having said that, this one is a safety issue, that VW felt strong enough about to recall the cars and have the mod done. You shouldn't have to buy the mod kit if it hasn't already been fitted, VW should still do it for free.............see previous posts.
Im thinking of buying a by-pass valve kit. Is it an important mod. Im a bit wary as ive noticed alot of members have had problems 
If its not broken then dont fix it?