Honestly, I have to agree that Cliffy B has come out of left field with this comment. Any intelligent person knows that you don't knock your competition, because they'll run right over you. So really, his comment is just an unfounded jab at Konami.
On the other hand, I've actually played MGS4, and beaten it (though I don't know if Cliffy B has done so). MGS4 is, to me, the culmination of every MGS game thus far, rolled into one, and punctuated with improved movement, stealth and story. I understand some people may not enjoy sitting through long cut scenes, but that's just tough. What's a game going to be like without a structure set forth by a story? What, are we all going to be playing shooters and puzzle games without stories?
Anyway, not to get off point, but I think MGS4 was innovative as far as the series is concerned. There are definitely some things it could've done without. I won't go into specifics, because I don't want to spoil anything for anyone who's not played the game yet. What I will say is, if you haven't played it, but you already don't like it, I suggest you rent it and play it for a few hours. Give it an honest shot. If you still don't like it after that, well, at least you know for sure. For those who haven't gotten it, but love the series, GET IT. You won't be disappointed.