I've heard the "rule" about not using patterns with straight lines or boxes -- but I'm finding that it can work out just fine, particularly if you are not going to obsess about having every little match point fit together perfectly -- the overall effect, from a distance you'd normally have from a quilt on a bed or wall, is just fine.
That said, if I really loved a fabric, I would be hesitant to use it in a OBW, since you're left with the colors and little hints of the original pattern, but you lose the original fabrics.
RST