I enjoyed it, and I too am not a Duke fanboy, though I dug Duke3D.
This is just an old-school shooter at heart, and yeah the graphics aren't flash (though they look good in parts), but like art, beauty is in the eye of the beholder.
It really isn't that bad a game as most are making it out to be. DNF is better than MW2 IMHO.
I went in to play it without listening to all the hate and vitriol, and I enjoyed it. And the extras when you finish it are pretty cool too, although playable versions of the previous Duke games would have been excellent. It deserves a 7/10. I'm not saying it doesn't have flaws, but really, there are much worse FPS out there.
I love reading all the backstory and history, legends, and mythology of the game worlds. In games like Dragon Age it can get to the point where you skip some of them, but generally I like to acquaint myself with the game world's history.
I reckon it's a decent game, and I am not a Duke fanboy.
Yeah, the graphics are stuck in another era, but some environments and characters look pretty good, and the gameplay is fun. It is just an old school shooter at heart. I don't think it is as bad as most believe; I would give it a 7/10 if I was reviewing it.
But it's true, it would be worth waiting until it's cheaper.