Otherwise, they differed significantly from each other, in nearly every facet of their game design.
For example, while the Traveller star-map was hex-based and the game used jump-drive technology, the 2300 Universe had a real near-space map, and a "stutter-warp drive" technology that limited per-trip travel to a maximum of roughly 7 light-years.
What I loved about 2300 was that near-star map. I had always wanted to play a sci-fi rpg that used actual starmaps. I remember spending countless hours poring over the star-data spreadsheets that accompanied the near-star map, and built my own stutterwarp route map.
I noticed that Far Future Enterprises / Quiklink Interactive announce that they are developing 2320, which is a sequel to 2300. I don't see a lot of evidence that the game or support materials are available yet, though.