I've just tried the latest addition to the "Bass to MIDI interface" market, and it is AMAZING! The latency is inconceivable, and it's a trip to play. I've often wanted to track my bass lines while simultaneously having them notated by software, and this will do the trick. Also, I'm looking forward to plugging this into my computer and seeing what sounds I can come up with to play via my bass, once the system is installed on my Spector. Here's a clip of Lee, the creator of FretTrax, showing me the system for the first time. The transition is seamless! What interfaces are you guys currently using, and how is the tracking?