I'm a clipper! If clipping a curved seam that has a lot of tension and stretching is ok. I really can't see why clipping a seam that has very little tension on it is bad. It seems to me that the curved seam would be more likely to fray than the straight seam. I'll also admit that when I first started quilting I didn't clip or swirl. My quilts are quilted on a domestic machine or on my frame quilter, both hate bulk. Even hand quilters will tell you that the less bulky the seam the easier it is to quilt. I've had many issues with leaving seams bulky. If Sharon Schambers can clip so can I. I'm sure you've heard of her. She wins big and museums buy her quilts. If clipping is good enough for the her it's good enough for me.