Excellent work. I teach bargello classes and am always amazed at the workmanship and color choices from quilters who usually say they would never attempt to make a bargello quilt because it looks so difficult. Then are thrilled when they find the ease of construction and choice of color produces a masterpiece. The quilting should not over shadow the design. I have made several twist patterns and found stitching straight lines that follow the flow of the twist is the best way. It accentuates the twist and does not distract from it.
The four corners and borders can be quilted in a design usually curved to contrast with all the straight lines in the design.
Happy quilting!
Severna