EvansPhysics
I was looking through the Return kit checklist and noticed that there is now an alternate servo listed for the Futaba S3003/S3004.

It looks like they can now be replaced with either the Hitec HS-422 or the Hitec HS425BB. At first glance, the Hitec servos seem to have virtually the same dimensions and specs as the Futaba servos (although I believe the rotation is reversed and they have a different spline pattern).

Does anyone on the forums have any experience with the Hitecs? Is there any practical difference such as durability, etc?

I've had trouble finding Futaba servos before and am guessing that the Hitecs are easier to find.
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jgraber
Easier to find is exactly the reason.
Specs show the Hitec servos have 24t splines rather than 25t F3 Futaba splines.
It has been reported that crossing 24t with 25t splines significantly reduces the torque capability.
 I haven't used any myself.    I've been experimenting with summer projects using cheap Hobby King servos.
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Zach M
I’ve used them for my RC planes and have never had a problem with them. 
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