I have used Netathlon and TourDegiro with my Computrainer. Both are computer animated online virtual reality cycling pc platforms.
I will rank each in order best to worse in the categories below:
Graphics – Zwift, Netathlon, TDG. Zwift wins by a mile here.
Connectivity ease/reliability - Zwift, TDG, Netathlon. Zwift wins by a bike length from TDG with Netathlon dropped. Netahlon has relatively frequent server issues.
The ride feel (hills, drafting, smoothness) - Netathlon, Zwift, TDG. Netathlon feels the smoothest and most realistic with hills and drafting. Zwift and TDG are a few bike lengths behind here. The resistance to watts/speed ratio are not quite right with the last 2- the feel in the hills and draft are unrealistic.