Wow! Thank you so much for the nice compliments, ladies!
As to how long this took, it was a little over two months, but I didn't work nonstop on it and I had other projects going on at the same time. On the other hand, I know I did have a week or two where I knit obsessively on it. In terms of hours, I have no idea. I actually kind of enjoy miles of stockinette stitch, as it's very zen. I can literally do it with my eyes closed, or with them staring at the tv. Right now I'm actually working on what sounds like the most boring knit ever, a black stockinette sweater, but it's going super fast.
By the way, the all saints sweater Angie linked to this evening is a very similar shape. I do think this type of cocoon shape is (perhaps surprisingly) very good for pear/hourglass shapes, provided the garment drapes well and is loose through the hips.