I quilt on a 26" Innova machine and I find it stitches much better if I go in one direction even for E2E. I used to stitch back and forth but my machine rules so I go with what works for her.
When piecing, then I stitch the rows back and forth as mentioned above to keep it from curling or curving. Just seems to work better that way.
But again, someone mentioned to go with what works for you and your machine.