My daughter and I have done the Hoopsister's mystery for the last four years. It's turned into somewhat of a summer tradition, though my daughter is more valiant than I am in finishing. Here are a few pictures. 2011 she did yellow/black, I did pink/gray. 2012 her oranges are 100% scrappy from an "orange" layer cake swap we did with LuvtooQuilt. 2013 Hoopsister's did a stained glass mystery with an option to do a solid. My daughter, who likes to do her own thing, did a scrappy top and minky back. She also pieced our "battilizer" from the previous years and used it for 100% of her quilt. It's beautiful!! This year she's doing an Alaskan theme with aurora borealis backing. I'm doing a Texas theme with Texas backing.
Some blocks take more time than others. And yes, they are generous in their fabric requirements. But, like I said, it's a tradition now.