If I'm in the middle of a rapid and have an oar pop out, or whatever, I want to know that the next, potentially critical, stroke I make will be effective. Call 'em "training wheels" or whatever, I'll stick with the oar rights. That said, I may get some of the convertible ones so I can feather the oars when rowing flatwater against the breeze. Maybe if I'd learned with free oars I'd be proud and smug about free oars...
I don't know if I classify as "expert" but I get the idea.
(Chickenshit Boaters Association member in good standing)
Nothing in the world is more yielding and gentle than water. Yet it has no equal for conquering the resistant and tough. The flexible can overcome the unbending; the soft can overcome the hard. - Lao Tse