I loved that episode of Star Trek. That’s a great method. Are there other Dr. Who arcs about alternate realities or timelines? Like Mirror, Mirror in STOS or the alt. reality Borg takeover in NG?
There was some amount of that during the David Tennant era.
But the good-Lazarus-vs.-evil-Lazarus thing is more like the relationship between the Doctor and the Master. The Master has been a recurring villain since the '70s.
I liked Colin Baker mainly because he wasn’t Peter Davison, who I found practically unwatchable. (Strangely, I found his practically-identical persona in A Very Peculiar Practice to be brilliant.)
Yes, I liked Campion very much, and was sad the series had so few episodes, but I think he played the Doctor as a much wetter character. I also liked All Creatures.
Inferno is quite good. I usually tolerate “alternate universe” stories as just an excuse for the actors to have some fun. But Inferno tries to make the most of that device.
I went on a binge of IIRC the first three seasons of Pertwee a while back. One thing I rarely hear remarked upon is that these stories had probably the best stunt work in all of Doctor Who. Believable fights, real falls and real crashes. Real helicopter stunts.
Another thing that stuck with me, not having seen these for like 20 years or so, is how effective Caroline John was as Liz Shaw. I was spoiled by her charisma and intelligence for those few episodes. I thought it was lame following her up with Katy Manning as Jo Grant, being a nice but relatively credulous and slow-witted companion for the Doctor to explain things to.
Not quite the first episode; if he started at 9 as reported here, that would have already been the Troughton years. (Not surprisingly, Capaldi’s Doctor has some strong traces of Troughton.)