Right. I bought a Roku 3 and upgraded to an Ultra. Everything seemed A-OK. Had to restart the Ultra a few times but didn't have any upgrade problems until something went sideways and I ended up putting the 3 back in service for a week until a promised update arrived to fix the Ultra.
Bought the second gen Ultra to get the enhancements - particularly the mute button. We've had periodic problems but they all seem to cluster around audio problems.
Most common problem right now is no audio. We'll watch an episode with no issues and then start the next episode and NO sound. Usually cleared by exiting the app and restarting the episode. When that doesn't work I pull the power on the Roku and that seems to fix it. Happens with Hulu, Prime, and YouTube. Oh, and sometimes with the news channels.
Overall I like Roku and don't plan on dumping it for a Google or Amazon product - too many hooks in them and Google's Android makes me want to strangle Sergey. If I'm going to drop Roku I'll look at Nvdia or one of the other players. Bottom line Roku has the most channels and appears to be the least channel biased.
FINAL THOUGHT/QUESTION - How often does anyone see these problems with a smart TV with Roku builtin?