From what I feel, "traditional" would be anything that has a repetitve block, and the block has a name, and a story behind it
Usually the quilt would have a border, and geometry of block placement is highly symmetrical.
However, I think it would be too restrictive to classify everything into 2 distinct categories. Nowadays, it is common to see traditional blocks using not so traditonal colors, placements, etc.
I like the contemporary feeling of non traditional quilts. But I have grown to learn that traditional quilt patterns have been around for so long, there must be an enduring beauty in them. I am exploring vintage and traditional patterns/blocks, but when I make them, I will add my personal touch - may it be placement, color, etc.
I am also into using non traditional quilting fabrics (indigenous fabrics, silks). So, do whatever calls to you, everything else is optional