I have liked using Bottom Line (60wt) in my bobbin for piecing or quilting with a 50 wt. on top. A bobbin with Bottom Line will last such a long time! I very much like Aurifil, So Fine, and Mettler Silk finish for quilting. But I use what I have and make adjustments. I bought a 6000 yard cone of Omni, which is 40 wt. a very long time ago for piecing and haven't quite gotten to the end of it. When using different thread weights, I sometimes have to make small adjustments when piecing because of the thickness of the thread affecting the seam allowances. On my old longarm, I haven't worried too much about lint, but it simply won't handle certain threads like Bottom Line, which locks up the bobbin. My new sit-down Bernina can handle anything I throw at her.