This has it advantages and disadvantages. One its great and requires less bandwidth, but also means that any floating calculation rounding issue can throw different machines out of sync from each other.
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.