Popular opinion has this as a good serial and fair play, they're right. It's well-paced, the characters are used in interesting ways, there are some really good cliff-hangers, and the whole story is compelling.

It's weakened by two main things. One is the fact that Davros comes back later in the show, but that's not their fault. The second is very much their fault, and it was the choice to make Davros so identifiably evil and other by making him visibly disabled