I thought E7 was difficult, I don't plan to do that again! But, if I HAD too I would piece it, then applique the strips.
I liked M3 because it was surprise. I expected it to be a killer block, and it was difficult for sure (my block isn't perfect!) but I pieced it and I was stunned when I was done, because all the pieces fit perfect for me! No ripping out on that one! Maybe it was just one of those rare perfect sewing moments!!! :)