I think they're passable, especially if colored correctly. I personally think that someone will eventually make a larger MP Grimlock, and I'm hoping it's either Takara or FT. I know I've said it before, but Quakewave is damn near as close to an MP as you can get without being officially from Takara. The iGear Coneheads are pretty close, too, but they didn't do much original design work on that one. Quakewave is seriously impressive, especially in-hand. And they've proven that they care, by doing things like shipping extra parts at no extra charge to all customers. That's fantastic service, if you ask me.
The only thing I'll dislike about their MP Dinobots is if they somehow don't finish all 4, and we're left with a slightly-short Grimlock. And damn, will it be a long wait until I have 5 dinobots!