[kylebrown]

The whole reason for quote stuffing, co-locating and competing on latency advantage is because the exchanges only accept quotes at one-penny increments and process them FIFO (first-in first-out). The restriction to one-penny quotes was relatively recent, before that the minimum increment was 1/8 of a dollar.

If the exchanges accepted quotes at fractions of a penny (for instance float values), then the speed/latency of quotes would take a backseat to price. It would make pointless a lot of the current shenanigans.