I had a RC stage 1+ on a PD in a 2005 Passat. Great Tune! Sold the car.
Currently have an RC 1+ and a DSG tune in my daughters' 2009 CR Jetta. It is a great combination. The transmission shifts much more smoothly than before, and sport mode is actually a sport mode. It holds the newly impressive torque much better than it did before.
The engine spins comfortably to higher rpm, pulls smoothly, gets slightly better fuel economy. The felt power from the buttdyno is massively improved. It will happily cause the wheelspin light to flicker in first gear on dry pavement, and will chirp second with authority. Passing is much easier, have not gone past 90mph, but it happily gets to 90 very quickly.
In my experience, Jeff is very easy to work with, listens well and has a lot of suggestions, will easily customize small things in your tune if needed.
Hope this helps.