Al is right there is no 'need' but there is a want.
Micro centering comes with a high price and not in just $'s... and the payback is that centering does more for our eye than anything you will receive in a contest.
However, Volz has a Digital being sold for the big guys and car guys. The AlumiStar.
It has features like a 'pressure relief' valve that lets off current to the stall servo, in order to protect motors and on board systems.
However, for sailplanes the requirements get tricky. Micro centering means a zero deadband, and that means buzzing. Buzzing is caused when the weight of the surfaces lean on the servo arm, the oh so manic digital amp is trying to force the arm to 'hold'. Buzzing ages the motors and its brushes, because instead of resting in a plus or minus position, they try to stay exactly where the TX stick tells them to be...good or bad.
Another potential problem with zervo dead band is flutter, when a surface flutters, that servo trys to push and pull in reaction to that flutter and actually has caused amplification to destruction.
Open that dead band up and you get less centering, as in your surface can be like a non digital ...plus or minus 1" :-) Not, actually such a micro amount that you couldn't see it at the arm, but in combination with linkage slop, mounting flex and gear lash, looks like 1/16".
Volz will offer a Digital version of the Micro Maxx and Wing Maxx X, Xp, and Hp, servos, when he is satisfied that it fits the criteria 'for use in high performance sailplanes'.
I still have about 40 old Micro Maxx servos in my planes and so far only work weekly in contests and on DS slopes :-) But then I'm not as cool as most :-) I just like to build and fly sailplanes.
So that's whats up with Volz. Most of that is on his website, and lots of other interesting stuff.
Gordy
Still in the ice in Kentucky :-(
I don't even want to think about what's under the snow in my yard.... I have TWO Catahoulas!!!! Not digital but eat a lot.
