Got Grimlock from Ontario last Friday and found Optimus this morning at my local TRU, so here's a quick review.
ROBOT MODE
DINO MODE
WITH VOYAGER GRIMLOCK
WITH DINOBOT RIDER OPTIMUS PRIME
What's to say? Grimlock's transformation is really simple (move the backpack up and clip it into place, move the arms back and clip them into place, straighten the legs and rotate the feet around), but still, he looks pretty good in both modes. A little gimmick here: spin the blue wheel to create some chomping action. Simple but effective. You can also sit Dinobot Rider Optimus Prime (or any other Dinobot Rider) on his back: just clip the crotch bar into his back and you're good to go. A fun pair.