I can't name check everyone, but I agree completely with what so many of you are saying! It really is good to know that I'm not alone.
DS and I had a frank discussion yesterday about his lack of effort. It was a rather long, circular and frustrating at times, conversation. From DS' point of view the crux of the issue appears to be that he did a vast amount (by his standards) of work for the November mocks (paper 1's) and felt he underperformed. He did very little work for his February mocks (paper 2's) and did very well. In his mind this equates to more work bad, less work good 
However, we know, as the school made it clear, the November mocks were marked very hard. they didn't want any student resting on their laurels. DS had also forgotten that the November mocks (and predicted grades) earned him a conditional offer to a super selective grammar for A Levels. So not quite the disaster he remembers.
Long story short-ish
we have compromised on 3 hours revision per day. He is now doing hour one of today on Chemistry 2. Later he's playing tennis then will do two more hours.
I am invested - as are you all with your children - in him getting the best results of which he is capable. Not because it matters to me, but because he will be so very pissed off if he doesn't get the grades he wants.
Anyway, Happy Thursday All!