I'm thinking low-level is the way to go with the Traveller game. Not so much in power level -- I don't plan on messing with character creation, at least on the first outing -- but in money, equipment, and variety of adventure.
Partially this is because I've been spending a lot of time looking at the trade tables. I expect they won't get quite as much attention once we start playing -- we'll too busy with the adventures, see -- but they still look like an interesting way to generate some on-the-fly excitement, and a quick way to decide where to go next. As long as they need cash, there's always something to do. Traveller has some handy mechanisms for keeping that need active -- mortgages and so on -- so this shouldn't be too hard.
Mostly, though, I want the PCs to have a sense of a larger universe. This goal may change once I get into the game and start seeing what clicks with my player group. But at least going into it, I want there to be a sense that there are things going on -- interstellar politics, trade deals, matters of empire -- that are just way out of their league. Not particularly important things, in the backwoods part of space they'll be in, more faraway, might matter if they cared things, but things nonetheless.