I've just ordered the CThreads poly on a cone. Prior to this I've used Superior Thread company which is my go to fav, but I have to admit to looking for something comparable at a cheaper price, so I'm going to do a comparison with the CT's poly.
My machine won't run anything like MaxiLock which probably is just as well :), My fav used to be Aurofil till I had a quilt come back with thread breakage and I've sworn off it since then. Not sure what happened there...
Superior's "Sew Fine" and "Bottom Line" are my favs overall.