Yeah, unless you have a entity count that exceeds your available bandwidth you're usually better off with a dead-reckoning system.

That also has the advantage of being able to "fake" events with effects until the server can resolve them meaning a latent connection can 'feel' faster.

Kudos to you for shipping a lockstep solution, we could never flush out the determinism bugs on our titles so we always just used dead-reckoning unless it was some dumb turn based game.

Depends on the mode the FPU is put into, fast or precise. If you want to have some fun, start a multiplayer game of AOE and switch the FPU mode from fast to precise. Doesn't take long to get out of sync, even for a basic game.