Great info, thanks for posting. One thing I don't understand is how one goo screws the sensors and another goo doesn't? The sensors are very well sealed units if you've ever held one and resistant to moisture and even some abuse. No question that the metal valve stem is going to get coated with the goo and will need to be changed during a new tire installation, but that's basically to be expected. Your choice of having an actual spare is what I'd personally do as well.