I was used to a much larger seam - 5/8" for sewing clothing, and going down to a 1/4" seam was very difficult for me. But the more I sewed that 1/4" seam, the better and easier it was. I can't even imagine trying to sew a 1/2 inch seam on a 1 or 2 inch HST. Fighting all that fabric would be hard. And, another point, all that extra bulk and weight from the wider seam is going to make all of your quilts heavier. That's okay if you are only doing lap or small throws, but the weight on a king size bed quilt would be too much for me. I'd be popping the piecing and quilting seams every time I tried to move the quilt. Washing the king would be a nightmare. Another point...You are going to have to reinvent the wheel on EVERY pattern you make because ALL patterns these days are written for the 1/4" seam unless you are doing miniatures which sometimes uses a 1/8" seam. Is there a particular reason you want to do the 1/2" seam?