In Gotham's Shadow is challenging to write for me. Its projected length is at least 50K because this story was intended to be my NaNo'07 project. Only once before I have written a story so long. Spirits That I Called was the NaNo'05 novel and is only a very rough draft. It isn't finished at all, it isn't even readable yet. After that I was so fed up I haven't been able to look at that pre-novel again so far. (Although I believe that it could become a real novel if I could bring myself to sit down and rewrite it.)
So my personal record is at 50K unfinished. The longest finished story is The Demon's Own at 4.9K. In Gotham's Shadow has just jumped over the 10K hurdle. It is quite respectable for me but now I am lagging and I haven't reached the middle yet. I wonder if I am not cut out to be a novel-length writer. The problem is that the plots I dream up are novel(la)-filling but the act of writing them down - this I find incredible hard.
So, fellow writers, what is the preferred story-length you are writing? Did you ever have similiar problems reaching novel-length? How do you maintain the motivation?
x-posted to kyrre and anvar