Hello Sodbuster.

Let me see if I can answer some of your questions. You're already familiar with analog servos, from 12 years ago, so no need to go into those.

The newer digital servos have a lot going for them. Their main assets are high torque, and the ability to maintain their under load, that is, if you deflect the servo "x" degrees, it will maintain that setting despite loads, and are much more precise. The con's are that they generally cost more and use more current, so a larger capacity battery pack is needed. Most upper end servos can run on 4.8 and 6.0V

A typical use for programmable servos would be, say, if you ganged 2 or 3 servos on one control surface, such as an aileron. You can program all three servos so that they all have the same end points, neutral points, etc. This way, they're not fighting each other.

I hope this might start a discussion going that will clarify things a bit more for you.

Bob