Who carrries Auriful? Thanks.

there are a number of places on line
CarmenWarehouse.com has the best price but very limited color choices, I usually only get neutral colors beige, tan, light and dark greys, and keep white and black on hand.
Also try ebay,
All That Thread.com should have all the colors and the YLI's silk and cotton.
Keepsake Quilting.com has a combo package that is a fair price. I use the orange spool,50wt., 1422 yards.
I just checked All That Thread, their price has dropped a $1 to $8.50 for 1422yds. This may seem high but one spool seams to last forever.

I use Coats &Clark Machine Quilting thread to piece, primarily. Sometimes Dual Purpose 100% cotton. For doing the quilting, my machine prefers Superior or YLI, but I use the Superior more. I bought a bunch of colors on large cones and am happily using them!!

I would say, bottomline is to try different kinds and see which one your machine likes. The 100% cotton (regardless of the price) was too linty for my machine. "It" really like the regular Coats and Clark I buy on sale at JoAnns.

If you have one of the child's red microscopes stuck in a closet somewhere, get it out and look at thread under the lens. You will be amazed at the difference in thread quality. I found some expensive brands to be full of slubs and some of the cheaper threads nothing but fuzz.

Even a magnifying glass will work. You're right - you will be surprised!

Does connectingthread's thread work well in a Pfaff machine?

They work fine on mine. I just prefer a thinner thread like Aurifil. Doesn't seem to take up as much 'seam'space.

My husband buys me Coats and Clark for hand quilting and Walmart for machine piecing.

My Pfaff's do not like Connecting Threads thread.