Read the Spec's on them and decide how much you want to pay and how much torque and speed you want from the servo. Compair the spec's from the above servo--^ with the ones Futaba makes. You will see that for the money Hitech has a much better servo.
I'm running this servo for steering. anything more than 180oz. is over kill on your batt pack. i paid $68 shipped new off fleabay
Hitech HS-5945MG http://www2.towerhobbies.com/cgi-bi...?&I=LXUZ85&P=ML
SPECS: Speed: 0.16 sec/60 degrees at 4.8V
Speed: 0.13 sec/60 degrees at 6.0V
Torque: 152.75 oz/in at 4.8V (9.6 kg/cm)
Torque: 180.53 oz/in at 6.0V (11.4 kg/cm)
Radio: 27MHz AM pistol grip TF-4 with steering dual rate, steering
and throttle trim, and high-torque steering servo with 70 oz/in
.20 sec. @ 4.8V or 90 oz./in & .16 sec. @ 6V
Radio: 27MHz AM pistol grip TF-4 with steering dual rate, steering
and throttle trim, and high-torque steering servo with 70 oz/in
.20 sec. @ 4.8V or 90 oz./in & .16 sec. @ 6V