I bought the T Guide. It doesn't move (It's screwed in) and I can position for scant quarter inch if I want to.
It's also far longer and no curve like the magnetic one. Means I can use the regular foot with no problem. Have had better luck using it. Disadvantage is getting it on and off.
What I don't like about the compensating foot is it's not marked as to where you would stop to turn a corner as in some binding methods. I did mark mine. I've mostly marked all the feet at 1/4 inch in from needle hole to front of foot.