I used to only use King Tut and So Fine, but then my nolting dealer turned me on to Glide thread. This stuff is amazing! It is just made for the longarm. I love the stitches, it seems to make perfect stitches and sits on the quilt top with just the right amount of "sink" into the top. I've had zero tension issues with it, using so fine in the bobbin. And compared to the King Tut, it is really inexpensive. The website is
http://www.bobbincentral.com/. They have several starter sets, including one recommended by Kimmy Brunner. On the cone, it appears to be very shiny, but it quilts up differently, with just a slight amount of shine, highly recommended!