Last year, I had a go at NaNoWriMo.  It was fun.  It was random.  It was a race to get enough words written every night, even if they didn't make sense and there were far too many adverbs.
I understand some people go on to turn their NaNo novels into proper WIPs.  In my case, I mined it for useful back story and characters for my actual WIP, which was only a fledgling itself at the time.  Turning the NaNo into a full story would have been very odd.  I made massive jumps in time when I got stuck - well, when I didn't just send my MC off to another town.  For some reason, she kept going to Whitby.  All the way from Wales.  She must have really liked Whitby.
There were a few scenes I liked and two characters who are now in my WIP, though one of them has assumed another character's name, and then changed hair-colour and changed personality - but it's still him, goddammit.  It also filled in some history about a war, which is important to my understanding of the world of my WIP and may be useful later, if I ever write a sequel.
There were also many pages of people drinking tea, elaborate metaphors which served no real purpose, and at least two kidnappings.  And a house-party where almost no-one had a normal name.
During NaNo, I went to meet up with some other South Yorkshire writers in a coffee shop and spent an afternoon typing away in company.  That was fun.  Lots of fun.  I didn't make it to other meet-ups, as they tended to be in Sheffield and with people who were, on the whole, much younger and not in full time jobs, so they could hang out a lot more and at odd hours of the day.
This year, I have some buddies who I actually know, in real life and/or from writing, and will probably hang out on-line on our WordCloud group and discuss NaNo progress.  I look forwards to sharing tips and prompts if we get stuck.
NaNo really is the time just to let rip and gallop through a tangled plot, not worrying about pruning or shaping.  In my case, I ended up with a wild garden, from which I stole some roses before scarpering, but it was a worthwhile experience and I am happy to be planning on a repeat.
I steadfastly refuse to plan for my novel, of course.  That is the bit which keeps holding me up with my WIP, and that sucker is something I want to get published.  The pressure in that thought might be what is stopping me.  The NaNo experience will not be planned.  It will be the mad growth of weeds and flowers that is was last year and I will enjoy the freedom.