Most of their designer named fabrics are really nice - nicer that some LQS that I have been to. But you just have to make that decision yourself. Unless it is something that I have bought before, I never order fabric on line from Joanns. I have purchased a sample piece and then ordered it on line with the SKU number when I have needed more than the store carries.
But then again before Walmart took their fabric out 4-5 years ago, they used to carry some really nice stuff. I don't know so much about now. The store that I go to doesn't have fabric and are not getting it back. You would be amazed at what you kind find at places. I just keep an open mind and spend my money judicially. I let my money speak for me. JMHO