Hardware acceleration still kind of sucks. You can get it to work, but the Jellyfin port of ffmpeg doesn’t work anywhere near as well as Plex’s.

pretty much just works for me on intel QSV. as long as you have drivers and hardware support it seems perfectly fine. Maybe plex has a cleaner implementation? Not sure, never used it.

Public network support is finicky. This is hard to quantify, but I’ve been on several remote networks where my Jellyfin connection dropped in and out and Plex did not. I suspect this is due to the Plex Relay service making up for bad routes between my house and the network.

depending on your network configuration, and routing of the network, this is most likely to be plex relays, this wouldn’t be a jellyfin issue, it would be a plex feature. You could easily fix this with a relay VPN server or something like that. (you probably shouldn’t publicly expose services these days anyway.)