[Helmtilt. Her optics don't so much as widen or narrow in her surprise, as brighten slightly.]

Unstable? While I can't argue uncontrollable, because Grim has always been a... strong individual, the one I know has a good grip on himself. Even if he usually speaks like something's been damaged.

[It's strange to think of Grimlock as... uncontrollable, in any other sense than a strong-minded individual who usually doesn't agree with Optimus Prime's way of doing things.]