My experience with Canyon bikes has been pretty good. Not that I've had to use their customer support very much, but I had a trivial issue with one bike that required them to send me a couple of small replacement parts. They were helpful and quick to respond.
I also had great customer support from Wahoo. I had a problem with my new Kickr Bike that required detailed technical support and they were outstanding. They diagnosed the problem and sent replacement parts on next day delivery. Really couldn't fault them on support.

I find in general that companies that are geared up primarily for direct sales (whatever industry) usually provide much better customer service than companies who have recently converted from using a more traditional distributor business model.