SuperSilentSin I don't really feel that I could create a book of quality with the 1 week time limit. I did my Cthulhu inspired book and only did 1 short chapter. While I do my main novel, I continue the other one with a weekly update. Even then I am unable to write longer chapters so the story is going at a steady pace.
I have come to decide that competitions are not fair. They don't seem to actually read what they accept as the winners so I refuse to participate in them anymore.
Make what you feel proud of. That is all I can say. It would be cool to get a book deal, but at the end of the day, you need to be proud of your work. I would say never write expecting to make a book deal. Only write if you enjoy it.