FWIW when I talked to Randy's Ring and Pinion, they told me they will not sell anyone the gov-lock, and that they still see problems with them on the brand new trucks.
Vehicle speed (in a roundabout way) and axle RPM differential are what make a gov-lock tick, stepping on the brakes doesn't work. The trick is to not let one wheel spin too FAST before it locks up. Of course, some come apart in the driveway, but mine have lasted me well. I just don't beat on them hard when I know only one tire has traction.