This is posed as a question because it's not something I can do myself, not owning a K-3 or K-5/II/s (the latter to indicated K-5, K-5II and K-5IIs). The reason I ask is because an article about Astrotracer and GPS posted today at the Pentax Forums reports that the authors found it consistently harder to calibrate Astrotracer on a K-1 and on a K-3II than on a K-3 with an O-GPS1. They apparently didn't do any rigorous testing with the K-3II - none they report, at any rate - but they make the claim for that model regardless.
I'm not doubting the veracity of the article as much as trying to find a larger sample size. With the number of variables at play it is dangerous to jump to conclusions based on a limited set of experiences. I do believe there are a few people here who have both a K-3II and one of the earlier models I mentioned and some of them might have used Astrotracer on both. If so, have you found Astrotracer any harder to calibrate on the K-3II than on a camera with the O-GPS1 unit attached?
