Moonhoney & Loretta,
I think the scant 1/4 inch seam is supposed to equal exactly 1/4 inch including the fold of the seam, which is why it is just a couple lines of thread difference. I know I've seen it in directions on older patterns and when learning from experienced quilters. My guess is that if an intricate pattern calls for it, you'd probably have to use the scant 1/4 or the whole thing will be off. Otherwise, 1/4 is fine.
I don't have the 1/4 foot yet...I'm old school with the masking tape LOL :lol: