I have horrible freezing problems with my x700...they are intermittent and I cannot determine a pattern that might explain it. Sometimes the player will stream for two hours before it locks up--other times it will lockup every 15-20 minutes--same streaming apps--happens on Prime as much as Netflix. It's maddening. Once it went into a hard lockup and wouldn't shut itself down or respond to the remote--had to unplug it, where usually when it freezes it will cut itself off. That's happened only once, but that is once too much. I even replaced all of my aging 5e cabling with brand-new Cat6 cabling just in case--did not improve the x700's freezing one iota. I tried everything--even setting the resolution to 1080P just to see if it made a difference--it didn't. I have a 4k TV HDR 10 55", btw.
So...bought a 2020 Roku Ultra--which downloaded and installed a bios update immediately. What a difference--using the same apps and the same network supporting the x700 (I only use wired networks) it hasn't frozen even once in the last week, although used for hours each day! That would be impossible for this x700--completely impossible. The image quality is noticeably superior to the x700's when streaming: ROKU claims to have used newer chips in the 2020 edition of the ultra--the image quality is simply better than the Sony (when the x700 is working in between freezes.) I have to say that those Roku reviewers on the 'net who complain about the ROKU's UI must be smokin' crack...
It's so simple and easy and intuitive it makes the Sony UI look like a Chinese water puzzle by comparison--which is just another strike against the x700, imo. I agree with ROKU--don't change it--you will just screw it up!
Tried my first 4k movie in the x700--a 2:15 movie that played perfectly until the last 20 minutes, when the player locked up--exactly like it does when streaming. This was a brand-new movie, carefully removed from the packaging by its edges--no fingers have ever touched the disk. I am very disappointed in this Sony. I was only surprised it didn't freeze much more often during the movie, but that is the intermittent nature of the problem. My last S3100 BR player never locked up streaming Netflix or Prime or playing Blu-ray disks. For some reason, AMZN dropped support for the S3100 player for Prime, although Netflix did not drop support for the S3100. Gave the S3100 away!
I tried to return the x700 to AMZN for an exchange, but was told that I could only get a refund because AMZN had discontinued selling the device direct. Go to the Amazon Sony store page today and the x700 says shipped and sold by Amazon! Guess I'll try Amazon again for an exchange. Don't want the refund--I want a 4k player that works as advertised. That last bios update for the x700 was March 2019--two years ago! It doesn't provide me with any confidence that there will ever be another update for this very buggy 4k player.