I used Mettler silk-finish cotton thread in my Bernina 1230 for years. Once I tried Aurifil 50wt 2-ply, I would never go back to Mettler. Aurifil is a much smoother thread that leaves much less lint.
Polyester thread is not at all linty compared to most cotton thread. Aurifil is the only cotton thread I have used that is similar to polyester in terms of not leaving lint in my machine.
It may have been true in the past that polyester was so strong it would break cotton threads, but that is no longer the case. Dr. Bob from Superior Threads demonstrates that in one of his educational videos. I think it's this one:
http://www.youtube.com/watch?v=9W5OxygKlUk