I just installed Go 4 on my Note 4, in parallel to the the Go 3. Aside from a few icon changes, everything looks to be the same. Take note however:
1) Any flight course history you have in the older version will not be on the new one - even after you log in/connect.
2) The map still will not follow the aircraft.
While it may just be my phone, I did want to relay that when flying my phone became so incredibly sluggish, the speed/telemetry data was updating about once every two or three seconds. The map was barely refreshing. At one point, when the MP was going through some severe TBE (that's another story), I tapped on the map - or so I thought. Nothing happened, so I did it again. About 10 seconds later, the map opened full screen, but wouldn't respond when I tried to recenter it over the MP. Instead, the buffered input of me tapping on it a few times kept switching the map and video about once every 5 seconds. I had to force close the app and restart it to get usable video/map data. Again, may just be my phone.