I am thinking about buying a MP and was wondering how level a spot has to be to calibrate the IMU? I have installed a level app on my Ipad and checked all of my countertops in my house. The countertops all come up +/- .2 degrees on both the X and Y axis. Is that close enough? I have also thought of going to the hardware store and buying some leveling compound and setting up a small location for calibration (this is where the OCD comes in). Any thoughts greatly appreciated.