Quite frankly, I think the only reason this is getting so much publicity, pre-release hype and praise is because it's Duke Nukem, people have been waiting 15+ years for it, and it's a sequel to an iconic franchise.
If this game was released under a new character, name, franchise, and all that, and had been in development for, let's say, 2 years, it would be dead in the water already.
Nobody would like it, want it, or give a shit about it.
Thus, I think that, on release, everyone'll be either a) dissapointed, or b) (Most likely) Everyone will continue the hype over the finish line, giving it the 10/10 and 5* ratings they think it deserves, before sobering up from the hype and coming to their senses, realizing it for the distinctly less impressive game it is, similiar to what happened to MW2.
Everyone loved the Multiplayer, but about 2-3 months after release many people, myself included, sort of woke up to how broken, unbalanced, and skullfuckingly broken it really was.
Except, with Duke, it'll be how average it is. Everything will work fine, but be underwhelming.