Those work fine but not as detailed as vagcom. I have a generic obd2 scanner. It's good to keep in the car for a quick scan. But if you really want to pin point an issue, vagcom. Plus you can charge your friends a case of beer to scan their cars, adjust idles, ect.
Good example of what a generic tool won't tell you. I had my steering wheel light on when I replaced my steering rack. Hooked it up and found this
Steering wheel was 360 out. Wasn't paying attention but I must have turned the wheel 1 full turn before I installed the shaft to the rack.
Also most scanners will not read ABS faults.