I actually like Grimlock and think he's cute in his own way, but in the hard-core realistic version of Transformers that I'd embrace (as long as it doesn't stray too far from G1), I don't really see a place for Dinobots (or massive size changes into Walkmans and handguns) unless Michael Bay can convince me otherwise. The G1 reason for Dinobots (Wheeljack's inventiveness) would be cool to see realized in live-action somehow -but very tricky to do realistically. We'll see where the movie franchise takes it.
I would've not bought Transformers at all and just appreciated it from afar, like Scooby-Doo or something, had it not been for the attraction Alternators had for me (and MPE Optimus Prime). Thus a very specific taste was cultivated in me in as far as Transformers are regarded. I've gone with that as I've picked and chosen what I purchased and would be a fan of.
So nothing against Grimlock. And he means more to me than Scooby-Doo, but compared with Optimus Prime - not a lot more.