Certainly before the days of lock up torque converters there was a big efficiency disadvantage. All sorts of folks complain about all sorts of things. This is my argument to trot out to point out that most complaining folks are hypocritical.
"Never explain, Never complain"
A good rule to live by (with rare exceptions).
I considered that as a possible motivation for your comments. Thanks for the clarification (and I'm not being a smart-aleck). It does take a developed skill to manipulate gears, one I'm proud to have. Learned it on a '72 VW. During the Michigan winter on icy roads.