As it has already been stated, I believe the argument over FOC Grimlock comes from those who are trying to fit him into their "classics" shelf. For those of us who actually played the game, he's a great, no perfect, fit for the FOC shelf! He looks as similar to his game model as any of the other FOC figures so far. In fact, he may resemble his game model better than all of the FOC figures save Starscream and Kickback.
I do wish his paint scheme was shiny gold and silver like the photos they showed us before, but I know those are always doctored up. Besides, I think Takara may release their version with the shiny paint should you really want that look (which I may get since I was thinking of getting two of these guys anyway).
Back to his overall look being pretty spot on to his FOC game model, this is the aligned version of Grimlock, which is a completely new version. For those of you interested, there is the TFP Rage of the Dinobots comic to connect Season 2 and 3 of TFP. This version of Grimlock also closely resembles the comic iteration as well with no wings, chest style, leg style and arms. So, to me they did a great job of giving us a figure of this aligned representation of Grimlock.
Thus, it seems to me that the only thing that would turn people off would be that he doesn't work for a G1/classic shelf. Otherwise, he's going to be front and center of my FOC shelf.
One last note, if FOC Grimlock doesn't sell well (which it looks like he won't be the hotcake I thought he would be) then I think we can kiss the possibility of getting the rest of the Dinobot team goodbye. That would be a shame because their FOC models are AMAZING! Dare I say, even better and more bad ass than their G1 selves. Really, FOC has given us the BEST version of ALL of the Dinobots to date. I hope those of us who played/enjoyed the game and are continuing to enjoy the aligned continuity of TFP, comics, etc. will support this guy so maybe the rest of the Dinobots will see the light of day. I remember reading that one of the decision makers at Hasbro said that he would like to see all of the FOC Dinobots become Voyager toys (from an old thread on here, I'm not going to try and dig it up).