David,
Don's buffing adapters are the easiest things in the world to use. One end is threaded to accept your lathe's spindle and the other end is threaded to accept your buffing wheels. To use, thread the adapter onto your lathe's spindle and then thread the buffing wheel's arbor into the adapter. Turn your lathe onto the correct speed. Load up the wheel with compound and buff away.
The system's greatest advantage is it's flexibility. You can mount larger and smaller wheels and different shaped buffs. So, it can be used for everything from big bowls to the pens. I have the 8" adapter, which easily lets me reach to the bottom of a fairly deep bowl. If I were buying today, I'd get the 12" adapter instead.
The only downside to the use of these adapters is that you have to remove and replace the wheels when switching between compounds. For small things items, the system that has three wheels spaced along an arbor (available from Don Pencil and from Beall) is more efficient since you can quickly move from one wheel to the next. However, it only takes a few seconds to change wheels with Don's adapter, so I prefer it (for the stuff I tend to make) to the three wheel systems.
Hope this helps.