I agree that pressing to the side was a necessity with hand stitching, but not necessary when you have a top and bottom thread and no gaps between stitches. That said, I prefer pressing to the side because I have much greater accuracy matching seams that nest. I will press open when a (usually more modern, large-piece quilt) pattern specifies it.
Barb in Louisiana, I have never before heard of seams popping! That must have been distressing.