I have had issues with Asus and the OS X wireless stack. I didn't have this router, but a different AC model and my Linux and Windows computers connected fine, both OS X and iOS would occasionally stall and time out, like there was random packet loss or something. I don't have the time to diagnose consumer gear so I got something else and haven't had issues. There are other reports of Asus routers and OS X issues out there, and maybe they've been resolved.
I think the days of consumer wifi are numbered however. Next setup is probably going to be ubiquiti or similar stuff with a real controller and options.