I use the Nexus 10 every day as a dedicated Roon Controller. The screen is great and no issues with speed. Aside from some teething issues it works very well. Only catch with it is RAM use climbs steadily with use, so generally the app needs restarting every few days.
If it is stable on your WiFi then you should be fine with it. My only concern is whether the rewritten Roon Android support will still work with these older versions when it comes out.