[ctlby]

Let me clarify: my random delay shuffles incoming orders, while random exchange delays (outside of CME iLink games) do not. Removing determinism hugely hurts speed.

The value of further decimalization seems questionable. It would in all cases reduce displayed size. Would transaction costs still decline due to tighter spreads? For the liquid lower-priced stocks, probably. For stocks whose natural spread is > 1 cent (most of the expensive stuff), certainly not. For everything else, hard to say.

Maybe a Japan/Europe-style tick increment schedule is a good compromise.