It might also be interesting (assuming you are using Repetier or something like that) to turn off the settings where it sends updates to the LCD screen you have. I found that with Repetier Server it was causing the gcode parsing to occasionally miss steps or move in the wrong direction. The symptoms are similar to your stuttering issue. (Root cause on mine seems to be that Marlin doesn’t parse out the updates to the LCD quite properly for special characters.) Turning it off seems to resolve the issue for me.