It is up to you what you want. The quilting can impact the design and how the eye sees the quilt. Stitch in the ditch will reinforce the linear geometric pattern of the log cabin blocks.
Something curvier will soften the rectangular pattern of the block pieces.
If you want to emphasize the rows and furrows layout you could do dimensional quilting that follows the layout.
It is amazing how the quilting can change the look of the finished quilt.