Plex is the least nightmarish of the video library apps I've used in the last few years (Plex and Kodi are the only ones I've ended up using extensively, though I've tried out several others).
Transcoding is obviously a last resort, but I've used it on rare occasions for streaming live and recorded TV from home to the Plex app on my iPhone and it works reasonably well. For my home theater stuff I absolutely don't want any transcoding at all, and Plex is generally smart enough to figure out what formats my playback device is able to decode on its own. When I first got a Chromecast Ultra, I had to fiddle with some XML config files in Plex because Plex was only aware of the non-4k Chromecast and thus would try to transcode 4k content, but I believe that Plex resolved that issue fairly quickly.
The issues I had were that, first of all, Plex server wouldn't run on my ARM-based Synology, and then later, I think there was a build for it, but it didn't have the horsepower to transcode, and it seems like it ALWAYS wanted to transcode things.
I've also tried running Plex server on my Win7 HTPC with the volume mounted over CIFS, but I had various issues with that; for one, having to reindex the volume means I have to either wait 15 minutes to watch something I just procured, or manually login and force a refresh which is annoying when I just want to browse files. It's been awhile, but I have tried a number of approaches (including Plex server on OS X) and none of them were satisfactory. Furthermore, I could never figure out why any of it was preferable to simply having a media player read files from a network store and play them. I don't care about "album art" type stuff; I don't download/store/play hollywood movies or music, so those features would be irrelevant even if I cared about them in general.
The one nice thing about Plex is I now have a few friends sharing their libraries with me over the internet. It's a cool feature, but I'm only using it from the client side, and I typically forget to even consult their libraries before paying to rent content.
Yeah, I just have mine running on my primary desktop (an iMac), but I've done a bit of research on consumer NAS products and the Plex support definitely seems spotty.
As for Plex wanting to transcode things, I mentioned having some issues with my Chromecast Ultra, but even that wasn't too bad. There should definitely be an option to not transcode video at all and let my playback device tell me that if it really can't decode the file. As far as I could tell, that option doesn't exist.
I haven't had any issues with library refreshing with Plex on my iMac and movies shared over SMB from my Linux file server. Plex seems to watch the shares and do small incremental refreshes for new content very quickly.
> I don't care about "album art" type stuff; I don't download/store/play hollywood movies or music, so those features would be irrelevant even if I cared about them in general.
That's definitely valid. Wouldn't basically any playback device that supports DLNA (and can decode your files) work fine for that? For me, the library features are pretty important. I had done a lot of work getting Kodi on my Raspberry Pi setup how I liked it, then I switched to Plex which is just as good or better but with a lot less work and maintenance.
Transcoding is obviously a last resort, but I've used it on rare occasions for streaming live and recorded TV from home to the Plex app on my iPhone and it works reasonably well. For my home theater stuff I absolutely don't want any transcoding at all, and Plex is generally smart enough to figure out what formats my playback device is able to decode on its own. When I first got a Chromecast Ultra, I had to fiddle with some XML config files in Plex because Plex was only aware of the non-4k Chromecast and thus would try to transcode 4k content, but I believe that Plex resolved that issue fairly quickly.