Like many have alluded to already in this thread, back in the "good old days", we used whatever servos we had: S148's, S28's, KPS 14's or 15's. Plastic/nylon gears and torque only in the low 40 oz. range, and I for one never had a problem. Looking back, one might think we were very lucky to have not striped gears or drained battery packs due to stalled servos. Digital servos are everything other responses in this thread say they are, but for me to use them, I have to soften them with so much expo that a nice coreless ball bearing servo that's a little slower can end up doing just as good a job. Ballistic old style pattern was set up for "slow" servos. We didn't need the instant response of today's digitals. Whether you go digital or coreless, I would suggest metal gears.