Jreceiver was available prior to Trio. Jreceiver overcame some ARM issues:
1. it crashed if more than 2000 entries in a menu item(album, artist,playlist). Jreceiver limit the list to 2000.
2. had no internet radio (shoutcast) capability.
Jreceiver can be a pain to install, and support is not great at the moment.
Trio has made things easier to use, the queue and play and synchronisation the main ones but it still relies on either ARM or Jrec 0.2.4(or later).
If Trio moves on to support another server, it may well be that eveyone will move over to this.