Here is a thread chart from Coats and Clark. I have no problem with Coats but I have read it will put grooves in machine tension disks faster than other thread. If you have a new rather touchy machine I wouldn't use it for peicing or quilting. I have an vintage Singer that could probably sew bobwire if I wanted. :D I really can't find the definite answer to why Coats has such a bad reputation)
[/url] http://www.coatsandclark.com/Products/Sewing/Threads/Coats+Sewing+Thread+Advisor.htm[url]