I would love to hear more discussion about Traveller campaigns, adventures and game sessions, from any edition. Every edition I've followed seems to attract more rules discussion and less adventure discussion than some other rpgs.
Cepheus rules discussion probably belongs somewhere else now. Although the earliest Cepheus was pretty much the 1e Mongoose SRD with worse editing, later editions have made more of an effort to distinguish themselves, and its apparent the publisher and many of its fans consider it it's own separate game now.
Citizens of the Imperium exists, and has a separate Cepheus forum. CotI can be a ghost town at times, possibly a consequence of splitting every edition and every possible non-edition topic off into their own sub-forums, but even that is apparently a result of consumer demand.