Watched Pyramids of Mars a few days ago. I guess this is part of the template that episodes like Hide or The Crimson Horror are based off of, where the Doctor and his companion are running around in the same building as the villain, causing mischief. When people say the cheap production values add a bit of charm, I think that definitely counts for the "Mummies" Sutekh had running around. They're slowly waddling around in the forest and have a ridiculous chest lump, but even basic stuff like chasing people through the forest felt tense. In fact, I think that's another part of how limited production values can enforce good plot discipline: they only have enough money to film outside a mansion, so everything has to stay geographically centered. With CGI now you can have the hero rocketing around to 4 different planets, but with that ability is the risk of having it all just be an empty slideshow.
I've only seen City of Death alongside this, so I'm still not too familiar with Tom Baker, but he does seem to play well between goofy irreverence and being slightly a prick. It's a shame Sarah Jane was a journalist in 1980 and not 1990, because maybe she wouldn't be stuck wearing a dress!