Surface Pro 4 Stylus sensitivity issues?

Has anyone had issues with Storyboard Pro on a Surface Pro 4? I’m trying the demo and light strokes seem unresponsive, then clunk suddenly into a medium range stroke. This isn’t the only app this issue appears in, (same in Blender w Grease Pencil, Flash is horrible, Photoshop is ok, Autodesk sketchbook and other bitmap based apps are ok, but still not as nice as cintiq). Just wondered if anyone had any suggestions/solutions? I tried lazy nezumi but that didn’t seem to help much.