Biggest new feature they could add would be to not have an additional screen taking up battery life and shining in my face, unable to be dimmed with f.lux. Maybe instead we could have a row of keys that provide some sort of function, and maybe a key that allows the user to escape. That would be a pretty useful feature that I can guarantee I would use dozens or hundreds of times a day. I'm considering replacing my Mac…
Most mac apps don't use function keys as shortcuts, so the old keyboard ended up being used for media keys (volume, brightness, play/pause, etc.).
The touch bar gives me a better version of that (I actually get a volume slider), plus more apps actually make use of that space to provide useful shortcuts now. And the scrub bar for media playback is really great when you have audio playing in the background.
Yes, you lose tactile feedback. But battery life doesn't seem to be a big problem. At least for me, it's been net positive.