I am hand stitching my hexies, but I do know people who machine stitch them. I do individual flowers. I then join the flowers into rows and then sew rows together. I have tried sewing some of the rows together by machine. It works OK, but as Geri said, it can be maddening. I'll stick to hand piecing. I always need a waiting room project anyway.
Both cutting line and sewing lines are printed on the hexies with Inklingo. The sewing lines make it very easy for me to match when putting them together.