Exactly why I switch saws to rim sprockets!! Might have had to skip out of the way of an odd chain or two over the years...Maybe on paper to an engineer, but in actual hard use the chain wears way into the spur and causes all kinds of problems. Whereas in a rim sprocket drive you just replace the rim. Also, since a spur drive can't float like a rim drive, your chain will come off easier when you snag it limbing. I never knew anybody in the woods who stuck with a spur drive.
What's favored in timed competition, I have no idea.