So far the only issues I've had with USB C is that I had to buy a Nintendo USB C cable to charge my switch and a separate USB C cable wouldn't charge my Pixel. It did work with an external hard drive so I know the cable wasn't completely broken.
I know there's other cables from some brands that might have worked, but after the 3rd one that wouldn't work for my switch I went for Nintendo.
I don't have a lot of USB C devices yet, so I'm hoping they get things ironed out.