My three rides so far with the 1040 indicate that the reported total ascent is about 10% less than that reported by the 1030. I have been fairly comfortable with the 1030's numbers as they are usually very close to the elevation gain reported by Google Earth Pro when I import a gpx file and view the profile.
I wonder if Garmin are using the previous algorithm to smooth the height data which is over-smoothing the more accurate height data created when using the multi-band GNSS option.
Has anyone else compared their total ascent data?