Don,

I don't believe a "Strong, Fast servo" would be a cause for worry. Sure there would be an instanteous increase in horizontal stabilizer load when the elevator is deflected. This instantaneous load will then equilibrate to a constant load until the elevator position is again changed.

The key issue with the RB stab is the poor build quality, mainly lack of glue and insufficient material in certain areas. When I was modifying my horizontal stabs and elevators for Robart Hinge Points, I found the trailing edge of the horizontal stab and the leading edge of the elevators to be manufactured with very thin stock, maybe 4mm thick. It's so thin there's insufficient material to drill and pin regular hinges. This is also true in the areas that receive the elevator torque rods. The other manufacturing flaw that may be contributing to the stab failures is the manner in which the slots for the CA Hinges are cut. The slits are excessively long and cut through the trailing / leading edges into the ribs. At the tips of the tail surfaces this probably isn't a issue, however at the torque rod end it is. I found the rib which supports for the rear tube spars split from the trailing edge all the way through to the hole for the tubular spar. If the builder isn't careful and doesn't adequetely glue the tubular spar and the ribs, also filling the split made during manufacture, failure of the horizontal stab is highly probable.

FWIW: I'll be installing dual Futaba metal geared, coreless mini-servos very near the elevators, with individual control rods to each elevator. Although this mod adds some tail weight I have full redundancy in the event of a servo failure. If I'm unlucky and have the classic RB tail failure, this feature might also allow me to get the RB back on the ground in a semi controlled fashion if only one side fails in a manner which doesn't prevent controlled flight.

Rich