Thanks for all the feedback everyone. Star Wars d6 was actually the first RPG book I bought, and I still own most of that line. Great, great game with an awesome system (well, except for the Wookiee-in-armor eating a thermal detonator issue...not that you can't fix that with Logic and GM fiat, but still, that was wonky). I own a bunch of Fading Suns stuff...doesn't really do it for me. Too many d10s, reminiscent of the Storyteller system which isn't my favorite.
S4--I'm more than familiar with Traveller's hard-SF roots. I insist on "harder" sci-fi even in my Alternity games, letting go fully of science only for Star Wars type games (which I usually call space fantasy, to even further differentiate from space opera, which can have harder SF elements). I think my feeling is that Traveller these days isn't so much insisting on hard sci-fi, so much as its just dated. Nanotech is probably more realistic now than ever before, and obviously Traveller computers are somewhat laughable considering what exists now. Cybernetics I do not consider to be particularly "soft" either, especially given recent advances in mating nerve cells to silicon chips (fascinating mechanisms too, if you've got the biology background).
I think I will just end up modding Alternity to suit my needs. I've already started on an alternate combat system to be a little bit more logical than the normal version is. The tech levels is probably just a matter of plugging in the tech definitions from another system. There are some difficulties involved, but nothing I can't work around given some time.
Thanks for all your comments and enjoy your Traveller! I'll be back when T5 is released...