I'm very happy with DTN/IQ's true-tick data feed and outstanding customer service; however, if you're using this data for system backtesting, an annoying omission is that the second stamp is not included. If you work with records that were not second-stamped upon arrival (in real-time) by your software, then you will get clumps at the top of each minute. I was told by DTN's customer service that a future upgrade to their software will add the second stamp to the feed, but the release date for this update is not yet specified.