From my understanding digital servo's have better resolution. They are smoother and return to center better than non-digital types. They also I'm told have greater holding power. They also use more current. I would say that in your trainer or Stuka the difference will be neglageable. But when you put together something aerobatic the digitals would come in handy. I fly Futaba and would recomend the 7 channel. There is nothing wrong with JR. I feel th futaba is a better bargain based on what you posted. When you get into scale the more channels available the better. If scale is where you are headed then the 7C is the way to go.

Mark Shuman