I wouldn't say Traveller is either just hard sci-fi or just space opera. Its system is hard scifi, and some elements of its setting (most aliens, the Imperium ruled by an aristocracy) are operatic. But these latter can be shed easily enough, and often were in actual play.
The artwork definitely doesn't help to promote the "hardness," true enough. But if you can wrest your eyes away from that, and instead check out something like this...
http://kemkem-web.hp.infoseek.co.jp/hukkou/hukkou.html
...you're golden. That's the kind of world in which the task resolution system feels just right, even today.