I went with a friend in 2010 and we took shuttles. We stayed at a Marriott across the highway from Hancocks. We were there 5 or 6 days, and there was one day where we could not catch a shuttle for 2-3 hours. They were packed completely full when they arrived, so we'd wait for the next one, which would also show up full. Other than that one day (which I think was either Friday or Saturday) the shuttles were fine.
You have to schedule some time for the quilt museum, of course, and we also went to Caryl Bryer Fallert's studio & store. The thing about Paducah is things are spread out, not all in one place like Houston is. So if you want to see everything, you either plan on taking the shuttles, or you plan on driving/parking/driving/parking.