Just wanted to share that. I know for many didnt work too well, but for me and others , most of the time it did work great. However, now that its leaving us I have been forced to get a seedbox/vps and find different ways to use google drive with the server. I managed to find a server that works well. During all of this searches I found some bitrate video tests (http://jell.yfish.us/) to compare network and playback performance and I used them to compared all 3 servers I am running atm and Plex Cloud smoked them all. Maybe its because I am not an expert on setting servers up, but they are working and playing normal 4k/hdr well so it isnt a bad comparison.
I downloaded those jelly bitrate test videos, put them all on google drive and added the library to all 2 servers (bytesized, ultraseedbox and plex cloud). I normall use my tv samsung ks to play 4k and 4khdr videos because it doesnt transcode anything, however these files are big in bitrate compared to the normal stuff (my tv set has a limit on how much speed i get from my internet network) so I tried with my xbox one s, which i never use because it performs really bad, everything gets transcoded… however for these videos, it was direct playing so it was perfect for the test 
Anyway so I loaded the jelly fish videos and I was amazed how while playing on Plex Cloud I could get the 250 and 300 mpbs bitrate videos to play without issues. Even the 400 didnt have any stutter or buffering, it did look to be less fluent at the beginning of the video but thats normal. I only get 400 - 450 mpbs from my internter provider.
Then I went to try with my other servers (I have 2 only because I am testing which one I wanna keep for good to replace plex cloud 
) they all performed ok in the normal bitrate range 70-140, even though they struggled a bit with 120 to 140); the 250 file played but it had a lot of stutter. The good thing, is that for normal big 4k movies my tv and those servers are working well so thats great, but to be honest the Plex Cloud has been really good and now with those videos I was able to prove it to myself.
Anyway, I know Plex Cloud is leaving. Some people had their problems but I just wanted to give the service some praise before it goes down, it made me really happy while it lasted. Many others tooo! good bye my friend lol
I know that its not a good business for Plex. BUT PLEASE ADMINS!!! Find a way to bring it back. I would be more than happy to pay to have a plex server with you guys. or allow us to use the google drive side of things on our own servers, for whatever reason your coding seems to work the best with google :).
