I heard of the scant 1/4" seam in my first quilting class over 10 years ago - I don't think it is a new concept. I don't have to worry about it much unless I'm doing stars that are supposed to match up. If I'm not careful I don't have nice points that match cleanly. It's also pretty important if you're doing block exchanges or trying to match up blocks with only a few pieces and blocks with lots of pieces. I find that I get great seams the first few hours, but my consistency drops with more time in front of the machine! I always joke that means it's time to stop and take a break.
Pam