This is a great box-set to buy, mainly because of the Second DVD, Silver Nemesis. It's got a great storyline, and is far easier for the average fan to follow than anything in the third season involving Sylvester McCoy as the Doctor.
The concept of this story revolves around three distinct threats to the earth, each representing a group that should never be allowed to seize power. There's also a fair smattering of comedy, which helps make up for the occasional plot-hole.
The other story, Revenge of the Cybermen, is fairly typical of the early Tom Baker years – an adequate story, told in a less-than-convincing manner. This story is most famous for it's extensive use of innuendo – it kind of belies the “G” rating…
Overall, I wasn't disappointed.