I used the for the first time yesterday, on a piece that I am doing quilt-as-you-go.  So I sewed through batting, plus 2 layers of fabric.  I also used a lightweight (50 weight) thread by Aurifil.  So far, it is sewing great.  No more "punching" through the fabric, glides easily, and am certainly pleased with the result (with the use of the particular thread I am using).  It's also used in a Bernina sewing machine.  I have not used this for embroidery, but if it sews the same, then I'd buy them again.  For embroidery, my main concern would be for the way the embroidery thread goes through the eye of the needle.