I have the 55" TCL Roku TV and it's been great. Roku is SO easy to use. I have a Chromecast Ultra hooked up to it via my Sony receiver, but you can still stream direct to the Roku if you want. If you already have a Chromecast dongle, just plug it into your HDMI and you're good to go.
Only thing you will need to get used to is the Roku remote. MUCH different than traditional remotes. I don't use mine, I just use my Harmony universal remote to do all the legwork.