If they claim they work, then they most likely work. I doubt they are just saying that to get more buyers. About the connection speed: I believe that so long as you are able to connect the ethernet adapter to the internet connection, whether using internet connection sharing or connecting it to a socket on your router, the speed does not matter. It should, at any speed be able to access the games, however, it really is suggested that you using broadband (512) as the game experience may be quite bad and laggy otherwise.