My preference is is bonded nylon, it jsut seems to make a neater stitch and in my yexperience with fixing machine, it is a little more user friendly. I have used Poly thread and it seems to get stranded a little more. Rarely do I have a problem with stranding with bonded polyester when the timing is right. Usually it can be attributed to the thread lot if it does. So, not to get in a debate, bonded nylon is what I stick with.
Dink, I asked once before if you had a store-front or are you home based. It was on another post so maybe you bever even saw it. However, I looked at your website and I was just wondering.
TM
Also, one time an old saddle maker told me he loved his poly dacron thread and went on and on about it, when we lifted up his spool, it said BONDED NYLON.