I am a new quilter, and I was told that "pressing open your seams" referred to how you treated the top of the fabric, not the bottom. As in: you iron the right side of the fabric so that you can make sure the seams are fully spread apart and not folded over slightly. Frankly, they way it is described above makes more sense.

Here is my take on the open seam-vs-seam to the side. I sewed clothing for many years. Seams were ALWAYS pressed open. I don't think that any quilt I will ever make will get as much stress on a seam as the seat of pants get. The seams on the seats of pants have to hold up very well and they are pressed open. Also, as a handquilter, it is so much easier to handquilt over open seams than the ones pressed to the side. I think with our modern machines and the better quality of our threads and fabrics, the old rule of pressing to one side is pretty much outdated. As for matching seams... I don't find it any harder to match open seams than "nesting" the ones pressed to one side. You just have to be careful, as you do with the nesting ones. I think we get into our comfort zones with techniques and are quick to dismiss different techniques because of the old "this is the way it's always been done" mentality. Just think if we still had to use scissors and templates instead of rotary cutters. I'm sure when rotary cutting first arrived, there were plenty of folks saying negative stuff about them. I think we need to keep an open mind.

Generally, I find it easier to "nest" the seams to get fairly close "matching" than when trying to line up pressed open seams.