I have the Rockler equivalent on my JET, and wouldn't want to be with out it, or at least a shop made alternative. The size of the table over the stock cast table is really a big bonus. Handles longer or larger stock with ease, and includes the t-tracks for quick clamping with toggle clamps. The fence is also a nice addition to a drill press, allowing you to easily drill holes along the same line or duplicate hole placement in multiple pieces. Has dust collection too. Not sure of all of the features of the FastTrack, but the Rockler version have replacable table inserts that can be drilled to accomodate sanding drums. All together a great product... Mine came in a package deal with the press, but it runs about $100 if I remember right.
-- Brian