The TCL P 607 and (LeEco Super4 to a lesser extent) changed my mind. Roku built in, one remote, arc/cec, can control the volume right from it. I can adjust tv and roku settings all without finding the other remote. I dont get in spots where I have to decide if the setting is a TV setting or a roku setting. I like the fire platform as well, and I could see their element tvs having a similar benefit. I'm still not a fan of samsung that much, lg has grown on me, and AndroidTV (leeco/sony) has some real nice polish to it in places. As long as they keep updating the roku, I am happy.
having used tcl, sony, leeco, lg, vizio, and amazon software somewhat extensively in the last year, I do now prefer the basic apps to just work right from the tv. its one less thing to troubleshoot. i didnt fully come to believe i liked smart tvs more until i started to notice how little bit worse the roku+vizio experience was than the roku/tcl experince. one phone app to control the device vs two. never having a cec problem. random hdcp failures are nonexistant.
I will say, it is telling my favorite smart tvs all run software made by other software companies, and not tv companies (Roku, Google, Amazon, Apple.)