So far, I have stuck to my schedule for finishing the final chapters of my book - writing 300 words every weekday means finishing a chapter every two weeks, which will mean it's mostly finished by the end of July when I will stop for the summer break. I'm currently a third of the way through chapter 23.
With the finish line in sight, it feels like I'm rushing slightly, and that what I'm writing isn't especially good. I made the mistake of glancing back to an earlier chapter to remind myself of something and realised that one of my characters has a totally different style of speaking at the beginning of the book to how I am writing him now. This is perhaps one of the pitfalls of writing over a long period of time (two years, in my case) - it's easier to become inconsistent.
However, my intention is to continue writing, even if I don't think it's great material, so that I have a completed first draft on schedule. Then, the rewriting can begin. Quite how long that will take, I don't know, but from this perspective I am looking forward to the satisfaction of resolving all the weak passages and inconsistencies currently litter the book.
I saw a great quote recently:
This makes sense to me, because the biggest obstacle to writing is simply sitting down and getting the words on the page. If I can get the entire book written, then any rewriting tasks should be easy by comparison.