Judy, like Jeanne, I pretty much use only the standard foot and the FMQ foot with the larger opening. I tried that "compensating foot" when I first bought the machine but found that for some reason, it was throwing me off and making my seams wonky. So that one sits in the box... LOL.
I'm going to try using the bar guide like Jeanne does. Right now I'm using one of the stick-on guides from Sew Steady, but sometimes I'd like something smaller that won't get in my way when I'm running at full speed down a jelly roll strip!
Edited to Add: Sorry, that seam guide is from "Sew Very Smooth" not Sew Steady. My bad. I have the whole set of sizes... bought them at a Sewing Expo a couple of years ago.