I am also a sock knitter. I knit a lot in the car since we are at least 1 1/2 hours to the nearest city of any size. I use the magic loop method and am a top down sock knitter. I have a book to learn toe up and will have to work on learning that method. I had not heard of replacing the heel. I am going to Utube and check out reinforcing the heels and toes. So far I have just mended them. Love to learn new things.