I bought one of those at a Paducah show a couple of years ago (the curved piecing tool) and haven't even taken it out of the bag I brought it home in. My mind just simply won't take it in enough to make my hands work it. To me, making those curved seams is on the same principle as putting in a "set-in sleeve" in a dress, and I have done that all my sewing life. I don't know why that didn't occur to me at the time of that demonstration. I guess it was just a matter of having more money than sense that day......