I use Connecting Threads threads. I like the price and I like the results that I get with it. Once in awhile the thread will jump off that little hook thingy that is at the top of the threading pattern. Just have to rethread machine and it's fine. I get the birds nest on the bottom when I start a seam after having used the thread cutter. The only way to not get the nest is to pull the threads out longer and hold them when you start the seam. I've had my 6600p for about 4 years now and it's still a work horse. Going to last me a long time.