I prefer sewing blocks that I have cut by hand, but the hands and arms have issues so I have a GO big (electric). I agree that getting straight of grain is a challenge, but if I take some extra time positioning the pieces I have managed. What I do know is that if I have a block that is a bit off, I either replace it or pair it with a perfect block so I can get the correct size block -- and yes I have had blocks off with the GO as well as by hand. I do find that starching the fabric heavily helps when either cutting by hand or using the GO.