Last year my sister and I were making the same exact quilt (BOM) and compared our first block. She followed the pattern's instructions about pressing to the side. I like to press open. My block was flatter, with nice crisp seams, and she wanted to know how I had managed it. I have quilted her quilt tops with side-pressed seams for her and found them to be difficult at times, where the bulk of the seams coming together made it difficult to quilt over. As a quilter, I prefer open seams; you get crisper lines, less bulk, and no humps to deal with.