Nice and clear out. Hopefully smooth, too. The Digitrak should be calibrated magnetically so that if the GPS course signal fails for some reason, the autopilot can still track a reliable magnetic course.
After taking off I found it was actually pretty bumpy. I flew out off the Newport/Huntington coast seeking smooth air. If there's a place to find smooth(er) air, it's over the water. Up at 6500' about 10 miles offshore, I finally found a patch of smooth air. I let the Digitrak do its thing -- you kick it into calibration mode, at which point it flies the four cardinal headings and collects magnetic data -- all automatically. You basically sit back and watch for traffic as it flies a box. It basically needs about 30 seconds of stabilized flight on each cardinal heading to collect enough data. Simple process.
After doing that, I plugged in a flight plan from present position to SNA to CNO, and popped the Digitrak into GPS tracking mode. It flew me home...what more can I say?
Since there's no GPSS or turn anticipation, it turned right toward Chino only after reaching SNA...so there was a period of about 30 seconds to a minute where it unavoidably had to recover from the turn. It basically teardropped back onto course. I can definitely live without GPSS. It's pretty rare that I'll be flying a flight plan with a turn of more than about 5-10 degrees. This turn in particular where it teardropped back onto course was more like 30+ degrees. I'd rather put the GPSS money into my gas tanks.