I have always been a press to the side gal. The leaders of my quilting group have been trying to convert us to pressing open and I have to admit sometimes it does make a cleaner, sharper block when the seams are open. I have not been converted but do press open on exchange blocks so everyone's blocks are the same or when it is a better choice for our block-of-the-month blocks. When an intersection will make a big-o-lump because of multiple seams, I will yield to pressing open.
In the end, there will always be more than one way to complete a task.