I didn't even try to do NaNoWriMo this year. It was a wise decision. I have far too much else happening in my life right now to add that pressure - but there's no doubt in my mind that it can be a worthwhile exercise. There have been some fairly derogatory comments going around this year - people saying that it is a waste of time, that you end up with a pile of unpublishable words, that 'real' writers don't do things like this.
Of course you don't end up with a novel that is complete and ready to send out. No-one thinking about it sensibly would expect that. What you do end up with is a first draft. It will need fixing. No-one will read it and fall at your feet and offer you the treasures of the universe for it in its present state but you will have done the basic starting work and you will have done it in a specified time and to a deadline. I don't know about you but that all sounds a pretty useful way for a writer to spend his or her time.
The claim that 'real' writers don't do this is even more ridiculous. They certainly do - and some of them even become bestsellers once they've worked them over.
Will I do Nanowrimo next year? I can't say yet but I certainly hope so.