I thought the ideas were really quite well thought out. I loved the way Helen gets dumped (from orbit!). The production design - right down to the painfully studio-bound go karts trying to be cars - was just a mess. I think they would have been better off just shooting it 'in the round' and be done with it.
As I said in another thread, I tend to watch that story and put this 'Sergio Leone' filter over the proceedings. Once you tune out the visuals and just soak the story in, it starts to work
McCoy definitely got better as time went on, but especially in Time and Rani, it's very painful to watch. Having said that, I don't think that anything was actually right about the show at that point. It's hard to choose a good production. There are just a few who are noticeably less flawed than the others

I mean, just what the frick was McCoy supposed to be doing during that cliffhanger in Dragonfire? At the time I was like "WTF?? What the hell was he doing there?" I had to rewind it a few times and I still can't figure it out. Then there is the pantomime space monster lit like like Shooting Stars. I could see that they were trying to ape 'Alien' but the whole thing is just so pathetic that it literally hurt to watch it. Then, when the whole 'CBBC' vibe had been established, suddenly this guy's face melts off. Great effect but time and place guys!
If I don't stop now, I'll never finish ranting about the McCoy era.