Daisey,
You asked how long they take to do. I cut & stacked and aligned my fabric, cut strips and 3 rows of triangles and pieced half haxagons in 3 1/2 hours for a quilt top that ended up being about 40" X 50". Now that's not including arranging them to get the final placement. But this method does go way faster than any other piecing method I've done.