For the price of the 820 and 830's they should be reliable. I don't care what kind of thread you put on them, they should sew well. I looked at them before I upgraded to my B 440QE and they just were to complex for me. I know some people who love theirs and others like you that are not happy. I hope you can get a good trade in deal at your dealer because sitting down to sew should not be frustrating!!