I started using this at the end of last month, and I'm really enjoying it. So far, it seems to be helping me get into the habit of writing regularly (which is what I wanted it for.
For anyone who doesn't know what the magic spreadsheet is and had the misfortune of clicking on this thread, I'll explain. It's essentially just a Google Doc spreadsheet (duh) where you input the number of words you write in a day. For every day you write 250 or more words you get a point. You also get combo points for each successive day you write. Once you hit a certain word count, you "level up", and have to hit a higher quota.