Spark plug Bosch or OEM Volkswagen

As for your plugs, bosch is deff the recommended brand, but just about any high quality plug designed for your engine will work fine. (im currently running platinum in mine, and their fine, but lots of people have reported idel issues with them.) The motor was designed around a copper plug, so thats what it should run on best. so bosch copper is deff the way to go.

newer Bosch plugs, cap, rotor (maybe 15k ago)

Recently replaced original spark plug wire set w/new Bosch; wire set, distributor cap, rotor, O2 sensor and Platinum spark plugs

I think that the recommended plug (and original equipment) is probably a Bosch Silver plug, and that is what I would probably stick to if I were you.

the car seems to run really good at the .028 with the bosch plugs

I've been researching spark plugs and i believe the oem's in Phaeton are Platinum. I am certainly going to verify that and will change mine to Iridium's. For the purpose of better power, performance, and fuel mileage.

Changed spark plugs, wires, cap/rotor with Bosch bits (w7dtc not those crappy +4s)

After I put them in (I was one of the first in my region to carry them and use them in my own car) I found a significant loss of power. Swapped those puppies out for some Bosch Supers and I was back to where I was before I put the Plats in.

Don't use those, they suck. The center electrode is tiny, and fouls easily. I've had problems with them, and so have others. They don't last for ****.

everything else runs pretty poorly on our cars. especially the bosch +4's