The diarama mode would have been cool, as the movie had so many scenes internally within Unicron that it would have been nice to homage.

But I think realistically, the diarama feature was not going to be a major part of the play pattern (if indeed any "play" will happen with most of the Unicrons purchased) that it makes sense to have removed for the sake of the design.

The blue maw is disappointing. I understand why people feel jilted by it - all production samples and prototypes seemed to indicate that it would be a wholly yellow maw the way it appeared in the movie, and is a very noticeable difference to the source inspiration. For it to be changed without warning or explanation at such a late stage is disappointing and somewhat betrays the trust and excitement that the process up to now had generated.

Will it stop me from enjoying this figure - no. Do I understand the anger - yes.