I like a thinner weight cotton thread for piecing, but I LOVE CT cotton for quilting! I've never found a knot or a slub, my machine loves it, and the price is unbeatable.
It's lintier than a "premium" thread would be, but it's not excessively linty.
I pretty much use their cotton exclusively for all my quilting, topstitching, and decorative stitching. It's so inexpensive (especially on sale) that I have at least 1 spool in pretty much every single color they offer, which is marvelous to have on hand! I never have to rush out to find matching thread, it's already right there in my drawer.