Sharon,
Yes, I use the Maxi-Loc serger thread on my APQS. Very rarely does it break or cause me any problems. I know different machines vary on how they operate. I gave the Superior thread to a friend who at that time had a Handy Quilter, and it worked fine on her machine. It is harder to find the Maxi-Loc thread anymore. I had to order it online the last time I needed a certain color.
Jeanine (Waal)