The playback on Roku apps seems more reliable wirelessly than the same individual apps on my wired PS4. Don't know why that is, but it's been a great, fuss-free option for me - Plex runs very well, and that's why I bought it.
I cut the cable cord about 3 months ago. All I really miss is the simplicity of cable. I thought the Roku would provide that but it doesn't. It takes a while to get where you want to go, especially on the ROKU stick. The ROKU stick is unresponsive a lot of times. It also seems that a button gets stuck a lot, leaving the menu scrolling for no reason at all.
Other than some delays in the Roku Stick responding to the remote control, I have been overall satisfied with the Roku entertainment offerings and the ease of use in navigating the screens.