I do not use either dealer in Calgary for service or custom work I do it myself.
I have used for the most part Syn3 but have changed to Amsoil and buy most of my maintenance materials at the North store. I have had to get a few things covered under warranty and have never had a problem.
I seem to have a leak on my shifter shaft now so I will see how that goes next week when I visit - my warranty expires in July.

 

As many have said here, they can tell you what type and what oil standard the oil you use must meet, they cannot tell you what brand to use, nor even who can change the oil as long as it meets common industry standards. However, sometimes fighting that bs can take a long time. Like when all the other Harley dealers in Alberta tried to refuse to do warranty work on bikes sold by House of Thunder because of the import BS. If you were told that by your dealer, I would give HD a call and bitch that they are telling people that.