I don't use the WM fabrics for my quilts, unless it's just a piece I need for an applique' or something like that. I used to work for a quilt shop and there is all the difference in the world in the quality. The prints and even the manufacturer may be the same, but it's not first runs...it may be 3rd ot 5th runs, which means the quality of the fabric itself is closer to the ends of the bolts. As with threads...the black and really dark colors are the lower qulities because they have been overdyed and overdyed ( this means they have been boiled way too many times which makes them less durable and sometimes "fuzzy". ) If you do buy WM fabrics, you probably should wash them well and then check for shrinkage and also for color loss....everytime they get washed the colors get less bright and crip.
This is just my opinion of course, but do keep this in mind. As for places like Hancocks and JoAnns...some of their fabrics are like this as well...they usually get the 2nd or 3rd runs of fabrics...seldom the first runs. Your best quality fabrics will normally come from your LQS....this is why they usually cost more and feel better.