I find stitch-in-the-ditch to be so stressful I no longer do it! It is much easier to use the walking foot and make wavy lines -- variations become part of the pattern. Just pull the sandwich from side to side as you feed it to the walking foot; makes soft wavy lines. Not sure what you are making, but here are some examples of what I am talking about
:
https://www.google.com/search?q=wavy...ed=0CAYQ_AUoAQ
I have used Aurifil 50wt 2-ply for both piecing and quilting on my domestic machine. It leaves *much* less lint than the threads you are using. It seems more expensive but, if you cost it out by the yard, it's not necessarily any more expensive than other threads. There are more yards on a spool because it is a fine thread. It leaves little lint because it is a very smooth thread. If you look at it next to a thread from one of the spools you are using, you will see the difference in "fuzz" on the thread. Aurifil 50wt 2-ply is too weak to use in my frame setup, however.
If I didn't use Aurifil on my domestic machine, I would use Presencia 60wt 3-ply. It is similar in size and quality, but the 3-ply makes it stronger than Aurifil. Aurifil is easier for me to find to purchase online.
I use Glide thread (
http://www.bobbincentral.com/quiltin...ead/glide.html ) almost exclusively in my midarm frame setup because it never shreds or breaks on me, plus it has a nice shine that adds a little sparkle to my quilts. It is also a great thread to use in a domestic machine. This is a thicker thread than Aurifil (and polyester instead of cotton) so the quilting thread is more apparent with it.
Edit: Just want to add that Aurifil and Presencia are great for piecing because they are very fine threads. I get better accuracy with my scant 1/4" seams because the thread is not taking up more of the turn-of-the-cloth. I think it is much harder to do accurate piecing with thick thread (such as the standard 50-wt 3-ply that you are probably using).