SoFine is thinner, and doesn't really have a sheen. It's draw is that it will blend in better. Superior's Omni is a little thicker and is what I use most on my HQ Avante. It does have a bit of a sheen.

One little thing that I learned from attending HQ training, is to realize that my quilting machine likes to go from left to right (right to left when you do pantographs from the back). So, if my thread is breaking, I can turn the needle a little to the right. If it skips stitches, I can turn it a little to the left. Turning the needle slightly to the right has helped me a lot!

I prefer SoFine #50 most of the time, but will also use Glide, which requires a larger needle but does have a sheen. Glide is not a Superior thread, but is readily available to me. I also like MicroQuilter from SoFine when I'm doing lots of microquilting or want to do heavy quilting. I also like Permacore if someone wants more of the look of cotton thread. I do not like to use cotton thread at all! I'd echo what others are saying about working on adjusting your tension also if that is the problem.

Do you have the Sweet Sixteen sit down (move the quilt) or the Simply Sixteen frame (move the machine)?

I have the HQ Sweet Sixteen sit down. I use a wide variety of threads, from 12 wt to 100 wt, cotton, silk poly, metallics. They all work fine. Every time I change my bobbin I check the bobbin tension and adjust as needed. Then I can fine tune the top tension. HQ has several good youtube videos that show how to do this.

Rob

What kind of issues are you having with your tension, specifically? Who told you it was the thread and did they explain why?

Love the glide & superior

My sitdown HQ16 does not like Superior Bottom Line. I could never make it stop breaking. I finally gave away all of my cones.

There has never been a problem with Superior So Fine. I use that the most.

I have the HQ16 sit down and it will take any thread I have. I normally use 30, 40 or 50 wt cotton. I always sew out a test and adjust the tension. If you are only adjusting the top tension and it still doesn't look good your bobbin tension needs adjusting. The service tech here told me I'd probably have to adjust both tensions every time I change thread types and weights. I thought that was just crazy, I could not get my tensions to look good so I took it in for service. $160.00 later, turns out it was the bobbin tension, it was too tight. Next time I'm frustrated and have tension issues I'll go with the advice from the service tech. So sit back relax, drink your favorite beverage and keep trying.

I know this wasn't what you asked, but thought I'd throw it out there.
Jamie Wallen has a great video on exactly how to adjust your tension on these machines. It was really helpful to me and cleared up a few misconceptions I had about thread and bobbins.

Watson

I use exclusively Connecting Threads Essential Pro. I do not quilt for $$. Mainly charity.

I did not get a bobbin winder with my used machine and buy Superior Prewounds called Bobs or something like that.

HQ has you make the tension a big tighter on the bobbin. I go by the Jamie Wallen video. You must always check under the little spring on the bobbin case as lint can get under there and affect the tension.

This combo has eliminated all tension problems for years. I keep it simple and it works well for me.

I have an HQ Sweet 16 and cannot recommend strongly enough that you consult their website for the HQ Live Archives. Monthly, 2nd Thursdays, they do a one-hour video tutorial on various aspects of their quilting machines. A few months ago they did one strictly on threading, adjusting, and a whole lot on tensions and their respective adjustments. I wouldn't miss them. Even when they're highlighting a machine that I don't have, I still pick up great tips. Just Google HandiQuilter and/or go to YouTube for a number of prior HQ Live presentations.