Well given how awful the source material was I can't imagine anyone else who could have made RotC/AoS remotely watchable (and despite the bad script and RLP's scenery chewing I actually enjoyed the episodes, especially watched as a single unit).

Simm's performance in The Sound of Drums was terribly uneven, I do hope he is toned down in the finale and actually has some menace.

I'm with you on Gallifrey though - I like the way they tapped into a post-Hogworts styling but still kept the mythos.