I use the VSS on my rally car with the little box.
Only issue I had was picking up the signal on the wrong side of the ECU. When I swaped motors in my Focus I had to switch the harness to a CAN BUS harness and when I picked up the signal after the ECU it was all CAN BUS craziness that caused the ODO to lose its mind. I traced the wire to the other side of the ECU and no problems since.
I would never mess with a wheel probe on a modern ish car. VSS or pickup the ABS signal from a wheel of your choice. You get the advantage of factory wiring, factory weather proof connectors, factory engineering to secure and protect the probe and pickup. My focus for example has a hole cast in the front knuckle that is super well protected. Heck you could leave all of the ABS sensor wiring in place and put a selector switch on your dash and switch between wheels if there was a problem.
