the problem is the shift rod itself, the aluminum threads eventually get pulled out.. i've never had a sensor go bad with the bazzaz setup, but i've been through a handful of shift rods, last year i got my hands on a steel rod instead of the aluminum from one of the STT coaches at BHF and i'll no longer worry about it.
Went with a Bazzaz 80mm shift rod. Every shift rod I have installed lasts about 5 - 6 moths......but those were all aluminum rods. The Bazzaz is a metal rod, so I think I have solved the problem. We shall see.