I also use it all the time, it went over an intersection of 6 seams on my OBW easily without veering off. If possible I would take the whole machine in and show them the problems you are having as it should work fine. It is big and bulky but so is everyother type of walking foot I have ever seen.
I have bought the open toed accufeed foot for paper piecing as well, as I love how evenly they feed the fabric.