Assuming that multiple devices can stream different content from a Plex server at the same time - which I'm not sure of either at the moment, is a Raspberry Pi 2 up to the job of transcoding 2 or more streams at a time?
To set some scope, whilst I might use it for some video, that would probably be the only transcoding job it was doing - if indeed transcoding was necessary, I'd think it will probably be streaming it in the same format most of the time. What I would like however is to move my entire CD collection to the Plex server in FLAC or similar lossless format, then be able to have at least two people able to access different tracks/albums at the same time.
I guess, that a lot of the time, as it will be streaming to another Pi plugged into a HiFi there would be no need for transcoding, but there will be times when it is steaming to a device on the same local network, and another over the web which will both require transcoding.
Regards
Tom