No time to post anything sensible but it didn’t exactly inspire me.
In summary:
Tennant good. Plot rubbish. Science insane. Tone all over the place. Incidental music genuinely abysmal. Billie Piper surprisingly good, again.
4/10 Could do better.
EDIT: What annoyed me was that all the flaws of the first season opener, which should surely be ironed-out by now, were here in spades – the intrusive background music, the moments of seriousness undercut by the silly rompiness of it all, and the generally breakneck, glib tone. This was actually less engaging than Rose, and utterly failed to re-establish the characters of the regulars: a ‘second pilot’, after all, should probably not revolve around a stupid body-swap farce in which your regulars aren’t acting normally. What characterisation we did get was broad-brush, sledgehammer unsubtle and designed to amp up the romantic tension by any and all means necessary. Just a mess, really. Bad series producer. Bad!