I just watched Logopolis, and it was pretty good, and much better than The Keeper of Traken. It was a solid story, not mind blowing but entertaining. The only big problem is that Tegan is extremely obnoxious. If I could change one thing about the story, it would be that The Master would use his tissue compressor on her, preferably as soon as possible. I'd only seen Tegan before when she'd been toned down and stopped complaining about going back to London, so seeing Tegan at her worst, which I've only heard of before, was more painful than I thought. Still, she didn't ruin the story, just made a few parts very annoying.
The 4th Doctor's end was sad, although more confusing than anything. Not in why he died and regenerated, thats obvious. The Watcher is the problem. I know Doctors 1,2,3,5,6,7,8,War,9,10, and 11 didn't merge with some pure white entity to regenerate, so having no explanation for why it was here now was bizarre. It almost feels like they made The Watcher to fix problems in the story (like how to get Nyssa to Logopolis), and then decided to tie him in with the regeneration. Anyway, overall it was a solid story, although far from my favorite last story for a Doctor.
Since this is the last Tom Baker story that I plan to watch (that I hadn't already seen, I won't be watching any story from The Power of Kroll to Warrior's Gate) I'll post a few thoughts. He was a pretty good Doctor. His first few seasons were the strongest, and by Key to Time the show was pretty much at rock bottom from a story quality perspective, but Tom baker was always good. I think he should have regenerated at the end of Season 15, at which point he would have been going out with a better legacy in my opinion. My favorite companion for The Doctor is probably a tie between Leela, K-9 and Sarah Jane. My least favorite companion is a tie between Romana II and Tegan. Romana II for her stupid comments in City of Death (which is the only time I've seen her, but she made a horrible impression), and Tegan because she was super irritating.
My favorite story is easily The Talons of Weng Chiang, followed by Genesis of the Daleks. My most hated is The Androids of Tara, with a special dishonorable mention to The City of Death, which almost certainly would have won the award if I could have made it through the whole story. Overall, the 4th Doctor isn't my favorite, but he was very good, and when his stories were good, they were generally very good.