There is a knack to reading Ben Aaronovitch's Doctor Who books. His first "Transit" works brilliantly once you except that you're not going to understand all of the slang and stop trying to keep up with the constant changes of location and just let the story wash over you. With "The Also People", you have to take on board that the story is not a fast paced rollercoster ride in the usuall Who manner and needs to be read slowerly. Then the book becomes not just brilliant but one of the high points of Doctor Who in any medium.
As well as being a great sci-fi novel of ideas (even if some of them are Ian M. Bank's, its not the first Doctor Who story to knick someone elses good ideas), its a great character piece and is also laugh-out-loud funny (The Doctor's conversations with a sentient parachute and talking fish are particular stand outs). The Seventh Doctor, Bernice and Chris are all at the best and Roz (a character who is on the surface completely unlikable) has propably her finest moments. Aaronovitch again shows that he's brilliant at writting machine's thought processes (he's the only author who can write Daleks well) and all the way through the book is a joy to read. The resolution to Kadiatu's story line requires knowledge of a number of past books, which means it isn't quite a stand alone classic, but this real doesn't matter. Perhaps the best thing about this book is the way it gives you a trip with the Doctor that you'd actually want to go on and an alien world you'd quite like to visit.