Well I won my first couple of matches, only losing to Serena Williams(challenge for her power serve), and I had all sort of problems with the control. It seemed like the M+ would only track what I was doing part of the time and constantly needed to be reset, often times in the middle of a match. I don't have that problem with Tiger Woods.
In TW M+ would track me fine for minutes at a time in regular golf and in disc golf(which I only played to test the tracking vs GST).
GST would work fine for the serve and the 1st return or two, but would need to be recalibrated again in the middle of the match.