Removing them loses about 10-20 ft/pd between 1000-4000rpm. I tested this on the dyno and played around with moving the RPM point at which they open, which was possible on the Autronic. Raised the level slightly because of my bigger cams.

For the complexity and expense, why would a big factory use such tecnology unless it had some real benefit. Most companies will do anything to save every dollar, because it translates to millions of dollars saved over a run of cars.

The cost in removing them only has benefits in your mind. So unless you are bored and have a tig welder, getting rid of them will only cost you money.

I too have noticed a little gum buildup, but that runner doesn't have an injector feeding it, so the gum is either blowby, or oil from turbo seals.

Hope this helps.

ps. After 250,000 kms, these may start to leak..it's at that time I would agree to remove them.