I like Gold-N-Rod's. Remember not to leave too much unsupported length and any control should be as straight as possible to reduce drag. Don't use oil as it will only pick up dust and cause drag. Clean and dry is best.
Ken is correct in that whenever a digital servo moves it does so at "FULL" power whereas an analog does not. That is one reason a digital draw more current. Even if only rotating one degree it is at full current/power for that moment.
The power switching can be compared to turning a faucet (analog servo) or flipping a wall switch (digital).