I have been using PS3 for years as a blu-ray player, never issues. For a while now i have been using PS4 as a blu-ray player. After a few movies that did not work and several freezes, no problem on regular blu-ray player, i am done. Now i using a sony S790 for blu-rays.
the PS3 was a great multimedia machine. As an amateur photographer, I loved coming home from a shoot and hooking my Nikon directly to the PS3 and I could copy all the photos down to the PS3 and then go thru them all on my big screen. I was able to copy all my MP3 collection to the PS3 and use it for digital music ( or stream from DLNA server ). I could copy video files to the PS3 and watch them. Bluray playback worked great! Apps like Vudu and Netflix were solid and consistent. It was fantastic!
Then the PS4 came out and I had high hopes. What a dud that turned out to be! Then PS4 Pro was announced without a 4k UHD drive. Another dud. This was a major disappointment to me after loving the PS3 so much. I pretty much gave up on Sony after that.
You guys don't have your old PS3's anymore? I have a PS4, but still regularly play PS3 games. It's too bad all of the old servers are going offline though. I guess they'll eventually get me to pay for a PS+ subscription to get through the paywall.