Firms with enough money to spend _can_ get a more accurate view of the market. The issue is proprietary data feeds. A trading platform is required to disseminate information to the consolidated tape at the same rate they do for a private feed, but that only holds for the "walls" of the trading platforms network. The consolidated tape is a LOT slower than a 100MB multicast feed being slurped up by a co-located server sitting 20 feet from the trading system.