Was just piecing on my QE4 and one of my favorite features is that I can be sewing happily along, run out of bobbin thread, the machine tells me AND I can change bobbins with the quilt or piece I'm working on still in place and then resume sewing. Simpley change the bobbin and resume sewing. If you haven't discovered this, give it a try the next time it happens. I've even done it while quilting on a quilted throw. I did purchase a package of 7 more bobbins from my dealer and I always wind 5 bobbins at a time as I hate winding bobbins. Also I tend to use Coats and Clark cotton machine quilting thread that I buy at JoAnn Fabrics. I was cautioned that it might not work on my machine and my instructor at the dealer was amazed that it was doing everything I needed her to show me beautifully including applique, embroidery and FMQ.