"So I have to move my head up and down all the time."I believe that for the use-case of Touch Bar as slider, it has similar behavioral characteristics as a trackpad. Do you use a trackpad? Or a mouse? Do you find yourself moving your eyes back and forth between the screen and the trackpad or mouse? Honest questions. I'm not trying to be snarky :)
As for custom keys, I think this has more in common with chording/key commands. There is the distinction that there aren't physical keys, but in the case of key commands, I know I'm not thinking, say, ⌘-Z when I undo. I'm just thinking Undo. And many key commands are application dependent. As I get used to whatever custom keys I've got programmed or are made available by an application, there'll be some period of acclimation, and then it'll just become habit. Perhaps to offset the lack of physical gaps between keys there will be larger target areas on the Touch Bar.
What do you think? Are these comparisons useful? If not, what are their limitations?
I do think the Touch Bar would benefit from some kind of haptic response, and I wouldn't be surprised if this is the direction it goes.
I also wouldn't be surprised if at some time in the future there is a touch screen for Macs. That doesn't mean that Apple is ready to release such a MacBook yet (for whatever reason), or that the Touch Bar isn't a valid feature. And while it's generating a lot of heat at this point, until there are a lot more hands-on (cough) reports, I think it's prudent to remember a lot of this is speculation, both for and against.
Edit to add: If you choose to down vote, please take the time to reply with a comment as well in the interest of communication. Thanks!