Let's talk about the earlier versions of Traveller and what we miss about it.
I miss the random phonetic alien character name generator.
I once a Vargar whose name was over 30 letters long.
Honestly, my title was really just a teaser to lure in folks that know the references. :)
The thing I REALLY miss about Traveller (mind you I haven't gotten to play anything like it since the early 90's) is the gritty realism of the universe and humanity in particular. I liked the lived in, rough feel of space-faring. It wasn't an antiseptic future where everyone had a ship, could fix it with a 'Multi-Phase Chakra Scanner' or even had the luxury of traveling off-world. A High Passage ate through your savings in no time. Humanity hadn't advanced, just the technology had. It felt 'near future' not far future... and there were no utopian cultures and none of the simplistic "all these guys are super good and all these guys are super-bad" paradigms. At least that is how we played it.
There is nothing quite like dropping onto a new world with your Library busted and trying to suss out the local tech level and law level before you run into trouble.
Mechanically, I liked the reality of level-less progress where your character would never advance so much that certain things ceased to be a threat. A Marine in full Battledress with a heated up FGMP is likely to burn your character down whether it is your first adventure or your forty-first. And the, for lack of a better phrase, hit point system is ingenious.