Leeson and Baker are I think the only creative links with the rest of Who. The series is set in a totalitarian future London in 2050, where civilisation has degenerated so badly that almost everyone now speaks with an Australian accent, and all buildings built since 2009 have been demolished. Also the climate seems to have become more tropical.
The central cast, apart from Leeson as K9, is the Professor (Robert Moloney), the only Canadian character ever to appear in the Whoniverse (or so I am told), accompanied by Starkey (Keegan Joyce) a bad boy hacker who becomes K9's special friend, Darius (Daniel Webber) who is a young rapscallion with an occasionally talking car, and Jorjie (Philippa Coulthard) as the core goodies.
Jorjie's mother June (Robyn Moore) inconveniently is something senior in the sinister Department which actually runs everything. She is actually the less sinister arm of the Department; she is locked in constant bureaucratic infighting with the evil but not terribly convincing Drake (Connor Van Vuuren) who is replaced partway through the season by the much more convincingly evil Thorne (Jared Robinson).
Who fans will be amused by the way that K9 regenerates in the first episode into a much cuter and smaller robot dog, with the ability to hover, fly, carry out detailed scientific analysis and engage in much more humorous banter than we have ever seen from any of the other versions of K9. All viewers will, I think, be irritatingly earwormed by the signature tune. But the format of the show is very much Monster Of The Week, with little pushing of the format boundaries. Even the first series of Torchwood managed better diversity of tone.
IMHO the best episodes, if you want to sample them, are The Lost Library of Ukko (although it must be pointed out that the library itself is not actually lost) and Taphony and the Time Loop. There is, however, a truly teeth-grindingly bad episode, The Cambridge Spy, which is mostly set on 23 November 1963. (Geddit?)
My recommendation to casual Who fans is that there is no real need to sit through all 26 episodes. The first two, the two in the middle that I have mentioned (plus The Curse of Anubis which has a coupe of amusingly subtle references to Who), and the last three are enough to give you a decent sense not only of what the show is about but also of why we are unlikely to see it again. (Though I see that Philippa Coulthard, who is lovely as K9's young friend Jorjie, was also one of the lead characters in Alien Surf Girls.)
OK, tomorrow it's The Eleventh Hour, again.