I come from sportbikes though so I know what truly useless looks like.
This ^
I've found my Gen II mirrors to be quite functional. Maybe it's all what you are used to. Surely these have to be more functional than a pair of Harley mirrors. I'd imagine with them attached to the paint shaker that you shouldn't be able to see a thing.
I agree about the improvement over sportbike mirrors, but they could be better. But, that is a minor gripe with such a great bike. I rode a BMW R1200RT recently and it had the low mount mirrors like my ST1300. Completely 100% useless. You could see nothing. We found that lots of the R1200RTs have been retrofitted with BMW bar mounted mirrors. My friend bought a set of these (not cheap!) and now can see what is behind him. I believe it is impossible to build any bike that fits everyone perfectly.
I don't have to imagine about the Harley mirrors. At certain RPM ranges, they are just as clear as anything else. Harley has that motor engineered to be quite pleasant at highway cruise speeds. At other speeds, useless is accurate. For example if stopped at a red light, don't even consider looking into them.