I have used both types, straight and bias. For me, straight is quick, uses less fabric and is trouble-free. But the finished edges seems stiff, to me, not supple and bendy, as the quilts bends. Bias takes longer to make, needs to be handled gently and carefully sewn to the sides. I always use bias when i have a stripe or a plaid. But the result is a luxurious feel to the suppleness of the quilt. I guess it could be compared to the difference between a Ford and a Cadillac. Both will get you there( a completed quilt), but what a difference in ride! Jmho. Do what works for you!