I didn't advocate for or against a TPMS mandate, but I don't want a third party system because a factory TPMS display will be built-into the car's instrument paenl, I don't need to velcro a separate TPMS display to my dashboard and either hardwire it or keep it charged. Plus I know that the OEM system is engineered for that car, I don't have to worry about installing repeaters because there's too much metal between the sensors and the receiver.
But that said, I do believe that the TPMS mandate is worthwhile, I've been alerted a couple times already to a nearly flat tire. (both times due to damage while driving, so I wouldn't have noticed it even if I checked my tire pressure every time I drive the car, which I doubt many people do)