I do both depending on the bulk. It is a personal preference matter (smile).

I'm an open presser! Yes, much less bulk. I'm also a hand quilter and have done SID with open seams and have yet to have a problem. Just remember, TANQP! Do what works for you.

you can't always press to the dark side. sometimes its necessary to press the seams open sometimes its necessary to press to the light. It many seams intersect you should press them open to reduce bulk. If you are putting two blocks together such as hst, you may have to press one to the light and one to the dark so they intersect.

to the dark side for quilt blocks, open for borders and binding

I've heard both ways. If I was going to be using the quilt for a child and it was going to be messed around with a lot, I wouldn't do them open because you don't have the strength you would have if you put them to one side. All you'd have is the seam threads holding it together and they can break if you have someone jumping on them and playing, whereas when it'd done to one side you have more strength.

If I was just doing a quilt or table runner or wallhanging for decorative purposes, I'd be tempted to do them open.

I was taught to press to the dark side but sometimes you can't, depending on the pattern. Also when I learned how make quilts hand quilting was the norm. I honestly don't think it matters how you press your seams. For me it's just what I'm used to.

I do whatever is necessary to reduce bulk in a block. If possible I press toward the darker side but if not I don't fret. and for lots of complicated triangle blocks, I'll press the seam open.

I have been been pressing open for almost fourty years. Never had a quilt with seams that broke or batting that poked through. Most newer battings have a scrim that keeps the batting from migrating.
It is a preference , I like a flat block, and it makes it easy when it comes to joining blocks ...as I never have two joining with the same direction,at the same point, making for a really big bulk at the join.
There have been a few occasions that I have pressed to the dark , only because it is a bit faster.

I had been pressing seams open, but, with small seams and getting older it's harder for me. The last quilt I made, I pressed to the dark side, easier for me, but, a little bulky in the corner where 4 blocks joined together. When I tied the quilt, those ties took care of most of them

I find sometimes when I press to the dark side, the seam doesn't go perfectly flat and my pieces end up a shade too small...very frustrating! I prefer seams open and haven't had any trouble, other than sometimes they don't want to stay where I put them!