I'm 27k into the third draft. Having come to a nasty impasse three quarters of the way through the book, I realised it is just easier to rewrite than find all the blind ends, name changes and dodgy information. I'm also completely distracted by my back, which will need specialised treatment and is undergoing all sorts of exotic tests. Despite this, I'm pottering on with the book, most days.
I like to get into a rhythm when I'm writing, same time, every day and set myself a word target, but at the moment with builders in and out, the stupid spine and kids going off to college/uni/WWoofing my life isn't that organised! I shall just have to write when I can.
One odd symptom of my back problem - or more likely, the painkillers - is a problem finding words. The last few weeks I've had real problems sorting out my vocabulary and it's hard to keep my concentration going. So I'm quite pleased with 27k but I have a deadline for the end of September for the whole book, so I shall keep going. Even if my words get a bit stuck on occasion!