Not so much contradicting as expressing another experience, but I
found friction shifting 10 cogs with dt friction shifters (albeit
Retrofrictions, the best of the best) was absolutely delightful;
easier in fact by quite a bit than shifting the 5 and 6 speed
freewheels on the trike using the same shifter; but a long cage,
pre-indexed Shimano 600 rd instead of a 8-sp era Dura Ace as with the
10, so that may have made the difference; or the difference may have
been that the HG ramps just made shifting easier. Dunno.
My current Fargo shifts 7 cogs spaced like 9 sp cogs with Silver bar
end shifters; and it too is fine despite the non-sequential cogs
(since the cassettes are home made).
No problems when wearing hats or balaclavas, either.
Horses for courses.
That said, the absolutely most foolproof and thought-free shifting I
ever used was a 7 speed, Sante group indexed Uniglide cassette with dt
indexing. Click, click, click and it went perfectly every time.