You should in theory have perfect stitching on this model. I have seen the most impressive freehand embroidery done on it, both very sheer fabrics and a bit heavier cotton. You might do the yo-yo test on the bobbin case and double check the needle. A lot has to do with even movement of the hands and steady speed. The knee lever controller is quite good, and you will develop a feel for it. The mechanism in there can be serviced and adjusted, carbon stack can be cleaned, it's often a DIY job unless you can find a repair guy who are willing to do it.