I had my Roku units prior to buying my 4KATV units and then Movies Anywhere came along which changed everything along with the Vudu app and Dolby Atmos support later on iTunes/4KATV.
I'm not surprise that the 4KATV picture looks better. I have a Roku and 4KATV in each of my three home theaters and I think the 4KATV outperforms the Roku in each HT location.
That's true. I can't watch any TV without at least 5.1 audio. My main HT has 7.2.4 Dolby Atmos setup, but my Bedroom and Computer/Office HT setups have 5.1 setup.