Diablo Predator handheld tuner/flasher for my car (and for all Fords) allows you to hook up their PC interface kit (serial to serial) to it and your PC and log and show specific data in real time...
I'm almost certain the data thruput (sampling) is MUCH higher than thru an ELM device, and it comes with Windows software for monitoring the real time data and viewing the logs...
I think I'm gonna go this route with the SVT Focus, as I'd like to flash a tune into the ECU anyways, and the adapter kit is under $40 anyhow....