"... Not a question about handlebar shapes so much, though input on that would be welcomed as well. Mostly interested in especially good-feeling hand-to-bar experiences. ..."

My first thought was that bar shape and placement and the same for brake levers and bar ends is of tantamount importance for hand comfort and should be completely dialed in before even thinking about padding, either on the bike or your hands. I have been known to go for rides with bare handlebars (or just enough electrical tape to keep cables where they belong) and the wrenches so can play with lever placement while on a ride.

I do always wear gloves, now cheap Performance gloves so that I am wearing them should I crash but on cooler days, I like the Dankin MTB gloves that are very thin and have no padding.

I should say that all my bikes are road bikes with quality steel forks, aluminum handlebars, aluminum rims and 32 X3 or (preferred) 36 X4 double-butted spoked wheels and I ride with less than max air pressure in my tires. I have haven't ridden bikes other than that in the past 40 years so my results may not apply to your experience.

And my opinion (which is sure to be unpopular with some) is that brifters are a step backwards, that making such an important part of the bike fit/comfort equation both expensive and time consuming to replace is putting the most important aspect of the bike, fit, on the back burner. (They have also driven a trend of relegating what can and I believe should be an ultimately hand friendly place to an afterthought; the drops. I set my bikes up to be all-day comfortable there with great brake lever access. Only then do I address the hoods.)

Ben