It appears to me that you are all concerned with the technicality of data rather than with the message that the data delivers.
dglynn is absolutely correct in what he explains. We had all this verified 4 months ago, but all these arguments are technical for the sake of technicality, although very interesting. The point I wish to make is that whilst everyone is nattering about the technical aspect of the datafeed, in terms of speed, no one seems to be concerned with what the data itself is showing.
What the datafeed is showing and what you all should be concentrating on is the sequence of pricing schedules, which are the clues as to which way the market is really heading, and on the ability to execute in a nanosecond a decision to buy or sell on the internet as a result of having developed instantaneous conditional reflex. This faculty is what everybody plays about with and no one attempts to perfect. Why ? It does not appear to be easy - but it is ! What you need to do is to develop the correct mindset and concentrate and what really matters, that is the ability to read the market, and to respond seamlessly. I recognise it takes between 4 to 6 years to develop this faculty also as a result of mindmapping the way the market really works, but just concentrating attention on what is mere detail does not lead to consistent success, which is and must be the ultimate object.