Not sure if this is because of my network, I don't think so, but wanted to raise these anyway. Hopefully they'll get fixed in the new release because using Plex right now is so hit and miss.
1. Stuttering-
As others have mentioned, stuttering as in every 5-10 seconds a slight pause then continues playing. At first I thought this was my network, and of course this is over wi-fi, but my X1 is perhaps 15ft from my router, and 15ft (through a wall) to my server. Running a speed test on my server (which is furthest from my router) I'm getting about 6 MB/s download. So I know wi-fi is pretty good overall.
This definitely seems to happen with larger files. Say a 1080P around 6GB+ will definitely stutter and is unwatchable. Same movie encoded at 720P around 1-2GB seems to be ok, most but not all of the time.
2. Resume-
I was watching a movie that got to about 1hr in then it started stuttering every 5 seconds. I stopped the movie, hit play again and it asked me to resume from the exact spot I left off. Hit OK. Then it started from the beginning again. So I fast forward to 1hr in, and it started from the beginning again. In fact, not matter what I try, this movie will ALWAYS now start from the beginning. Very weird,
3. Transcode CPU-
Wow. 200% transcoding MKV and assuming the cause of the stuttering.
4. Multiple transcode PIDS (unix).
Found that when stopping/starting videos (often because of stuttering) it will leave transcode sessions lingering, often each >100% CPU.
5. Low audio.
Audio is super low. Or is it just me?
6. Won't refresh if console is left on.
If a new movie is added to my library, I have to quit out of Plex and re-open it.
7. Quality settings.
As some others have mentioned, we need a global quality setting. Clearly Plex cannot handle max bitrates even over a fast network. Need to set it to 720P with a low bit rate and leave it that way, not have to select it for every movie.
8. Need genres for library.
That's about it for now. Hope to see these fixes in the next few releases.
Cheers.