[Thaxll]

Quake is vastly superior because the server actually run the simulation, for Serious Sam the server is basically a dumb relay.

[Jare]

It's not so much "vastly superior", it is more fit for its intended design and context. And certainly more sophisticated.

[iforgotpassword]

The server still runs the simulation for serious Sam and would kick any client getting out of sync (e.g. because they're cheating).