I am thinking of buying a rotating cutting mat. Joann's has a 50% off coupon I could use. I would appreciate your comments on the Olfa 12x12 for roughly $23.00, the Olfa17x17 for $40.00 or the Fiskars 14x14 for $25.00 after using the coupon. Would love to hear from anyone using either of these mats. I am going to use it for quilting.