I'm not that far (I don't think). I'm at the Hive now. All the enemies here are a real pain. I am loving the game though, I haven't tried the multiplayer yet, but I have heard good things about it. Overall, I have enjoyed my experience so far. I just wish I'd played Duke 3D before now too so I could compare it.
How far through Duke Nukem are you? I finished it the other day. I was not dissapointed. It done justice for me and I had played the originals. Also, the multiplayer is quote fun and with the whole "digs" things (levelling up in multiplayer unlocks new items and babes for you mansion), its most certainly keeping me entertained even after finishing the game.