Regarding EF, I purchased a sweater last year at NAS and it held up very well. I have no idea if it was made only for the sale? I suppose the way to tell is to look at the company website before purchasing to see if the exact same item is present there.
Vince cashmere sweaters however did not hold up as well. I have purchased some at the sale and some outside the sale. The sale version were problematic.
The sports bras I purchased last year were different than the typical style from the manufacturer because the elastic band was altered. I’m not sure if that was for the sale, or if Brooks, which took over Moving Comfort, changed the design. In any case, I have not had any issues even with heavy use.
The running shoes, Aasics Nimbus, which I was thrilled to see at the lowest price ever, have been fine. Miles of running pleasure as always and my feet and joints are happy.