I finally finished the premiere.
Jodie Whittaker found her stride toward the end of the episode, when she calmed the Smith/Tennant impersonation and the OTT line readings. I hope we will see the more low-key performances in future.
I liked the companions, especially Ryan, who felt like someone I'd never seen before as a companion. Yaz was fine - she reminded me more of a Torchwood character (minus the sex and being horribly murdered). I'm sure we'll learn more about her. I think Bradley Walsh is a good actor overall and has a warm screen presence, but I could see him "acting" a bit too much. I hope he'll settle down. I thought the woman who played Grace was very good and I wish she could have joined as well.
The plot was the usual Chibnall - flat and needlessly choppy and confusing (why did we get nothing of the guy who was being hunted after the Doctor dressed him down; what exactly was Grace even doing, as she just seemed to have a death wish; did the bad guy die or did he just disappear, and is the threat even over...??).
The ratings were great, and while they will of course fall, at least this shows a lot of people are still drawn to the program.