Well a definite improvement, while lacking the menace of the 4th Dr. story, this was an interesting idea, with Capaldi giving his best performance yet.Let's lose the annoying Guitar, and sonic specs though. 7/10
Probably the best of the season so far. Shame it was painfully obvious they only had two Zygon costumes and having re-watched Terror of the Zygons between episodes, they're not nearly as effective as the originals from 40-odd years ago.
I thought Jenna put in a cracking performance as Bonnie/Zygella but surely Peter's got to be up for a best actor award of some kind for that performance in part two!
Anyone else finding the lack of Clara odd, considering it's her final season? She only popped up for the last scene in 'The Woman Who Lived' and spent most of her time stuck in a pod for the Zygon two parter. I might be reading more in to it than I should but the part where the Doctor said that thinking Clara was dead was "the longest month of my life" seemed odd and I wondered if it was sowing the seeds for a later revelation... Or I might just be barking up the wrong tree ;-)
As for the guitar; I quite like it myself and can live with the specs for now but I'm hoping for a new screwdriver before the end of the season. Or perhaps Christmas?