This switch will work with the Roku devices. I'm using it with the "XR" at present. This switcher will not however auto switch between devices. It has a remote that can be used to switch HDMI ports or the button on the switch.
I use It With mine And It Works Just Fine, I Keep My Cable Box On Port 5 Because That's Always On And Roku On 4 So When The Roku Powers On, The Switch Will Detect A New Signal And Flip To It Automatically Based On Port Priority.
Mine has a roku hooked up, video goes through it and all, but the auto switching feature doesn't switch to it because it's always on and only goes into a screensaver mode. However, when you turn off another device, it switches back to one that still has a signal, so instead of turning on the roku to switch to the roku, you turn off the PS3 or whatever. That's a roku thing though and it'll be the same situation with any other automatic switch like this.
Yes it auto switches between the different devices as far as the roku I don't know if it works or not. Just make sure they include the power cable! My new one didn't come with the power cable and it would not work with out one!! The old one I have that is just like this only required power in order to use the IR remote the new one will not work at all with out one!