Transformation is far more like the classic Grimlock than other Masterpieces have been. Basically the same transformation, with a couple of extra steps on the tail/robot legs. I could do without the light-up feature, but it's nice enough. Poseability is incredible.
I actually now wish I'd gotten Masterpiece Skywarp. Ah well. It looks like some of them on eBay are actually cheaper than they were in-store. I might get him, after all.
Well, Chux - the light up feature probably won't last long. The wire connecting the fist to the battery compartment gets yanked a lot during transformation and came loose on mine. I need a sodering iron to get it reconnected. *grumble, grumble*