Complementary rather than competitive
I do not believe that is possible for an advantage player to have too much information. The more different independent sources one has available to gather information from, the better.
TrackJack is in it's infancy, and will improve with time. Perhaps it's biggest advantage is being in the form of a database that can be searched with a wide variety of criteria. You can look for a specific type of game within a specific area, or worldwide. You can make the search as specific or as broad as you like. And of course, the information can be continuously updated.
CBJN is the established standard against which others are judged. It has been around a while, and has established a justified reputation for accuracy. CBJN is what you stuff in your bag as you are packing for a trip, or study intently as you are planning one.
I certainly plan to take advantage of both services, and I imagine most other serious players will do the same.