Well Ihave been quilting for over 40 years.... and I prefer to press seams open on most quilts. There are some instances that I will press toward the dark , but for the most part I like the seams presses open. It typically creates a much flatter block. it makes even machine quilting easier , espically free motion, since there is a more uniform thickness, no "ridge" to get caught up on.
There are time that pressing to the dark will create a desired raised edge.
Quilts I have taken to be long arm quilted , the quilter is always surprised how easily/smoothy the machine moves over the quilt, and I comment that it is because I press open( majority of the time) . I have converted a few quilters on specific patterns to press open, when they see the results.