These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
It Will Never Catch On: TV critic AA Gill has been widely mocked for claiming the show would sink without trace when it first debuted; of course it has not only been going for more than a decade with very high viewing figures, but is also one of the most popular British export programmes.
Richard Briers, known for playing the pleasant Tom Good in The Good Life, played a villain in "Old Dogs".
Suspiciously Similar Substitute: Averted with Steve replacing Jack, as they are very different characters. Less averted for Dan replacing Brian, as they are both The Spock and have family issues (though different ones) and for Sasha replacing Sandra.
They Changed It, Now It Sucks: The reason Waterman is leaving the show - with the departure of all of the other members of the original cast Waterman has gone on record to say that he misses the chemistry he had with them and it's just not the same without them so he's decided to move on too.