Only thing I think it's useful for is calling Siri, and the finger print scanner. The latter really isn't a touchbar feature though, it just seamlessly blends into the touchbar.
The touchbar is gimmicky, but I still like it. It is pleasant. It isn't worse than the physical keys... but it's not really better either, if we're just talking productivity.
Apple won't admit that touchscreen is the way of the future, and updating the OS to accommodate a hybrid experience of touchscreen + keyboard + trackpad is the way to go. Some will disagree with me, but I think it's a matter of vision. As OS X stands, it's not particularly touchscreen friendly, that's for sure.
It's too soon to be critical of the Touch Bar. I can see plenty of ways it can be useful and it's useful when writing in Pages, for example. Also it appears like it will be useful for video editing.
Fingerprints on my screens is a big NO. I tolerate it on a iPad, but it's no fun if you like a clean clear display.
R.