[derefr]

It (as with most things) comes down to the implementation. If everything is rendered server-side, and the client is a dumb remote framebuffer, then yes, you'll notice 100ms of input lag. If, on the other hand, environments are composited on the server while the player's avatar and particles are texture-mapped server-side but then motion-tweened and composited into the environment on the client-side (which doesn't require much more work than the dumb remote framebuffer approach), then gameplay feels nearly as snappy as if everything were local.