I have a buddy who has the auto restart in his KT turbine and it saved his airplane when on the first few flights the engine flamed out (presumably from an air bubble in the fuel filter) and then it restarted and he was able to land. And this was in an F-18F.
I think this is EXACTLY where the auto restart can save you. And then again, I don't run fuel filters.
Frankly, I'm going to turn on all the auto restart functions in my engines that have that feature.