This may sound odd but its really true. Think about this....Goldman has 500 cars to do. There are only several brokers that execute orders for them. Everyone knows who they are. Pit traders, after standing next to these guys day after day learn to read the body language and the patterns of the large brokers. IE. .. When Broker X gets a large order, he gets a certain look on his face or the tone of his voice changes. Or, the behavior of the clerk at the Goldman Desk taking the order. Even worse...if the order gets arbed in.. guys see it and they front run it. Technically, this is illegal and shouldn't happen. Believe me, it does. Orders on the machine are completely devoid of these inherent inefficiencies.
Yup ..... The interesting part of game at the MERC. This will make things tougher for smaller traders IMHO: There are some benefits to owning a seat on the exchange .... I personally never enjoyed being covered in human spit by the end of the trading day in markets like the S&P500 or the EURO. Having adapted to all electronic trading some time ago I dont view the new "feature" as a big problem .....