Hate to be a Debbie Downer here but I think both Cringer and Roboto look terrible. Roboto mostly because of the design and Cringer because of the CGI. Roboto looks a bit bland, but maybe that is just one look and there will be a better look somewhere in the movie. Cringer just looks "fake" (I know CGI). His look isn't very sharp and seems like they didn't spend enough on the CGI in the budget for him.
Of course that could just be the teaser and he'll be better in the final cut.
As for the rest of the cast. Idris Elba as MAA looks good. The outfit definitely gives off MAA vibes while being different enough for a live action movie. Same with Teela. The guy playing Adam looks pretty spot on for my mind's eye of what a cartoon Adam could look like in live action.
The screen grabs I saw of Castle Greyskull look good and is that a Roton flying in the sky? If so I think I really like that design (double hoops spinning). Can't wait for the first trailer tomorrow and my concerns about Roboto and Cringer should hopefully be all for naught.