I'm glad that Optimus Maximus appears to be a one hit wonder (at least for now), cos I'm still not really fond of that concept. Having said that, I think that they're getting better and working in these special cameos. It's cool how they managed to weave Optimus Maximus' appearance into the overall tapestry of the ongoing saga, making it more than just a mundane gratuitous appearance. Still... could've been much worse.