Not particularly accurate. You need to use Golf Settings to adjust the on-watch Handicap Index every time your Handicap Index changes on your country's official handicap site. If you don't enter scores on the country site for every round you record with your watch, then the variance will be even greater since you are using two different data sets - the watch never communicates with your country's scoring site; Garmin can only calculate for the data they have stored on their site.
