I didn't use it in my R-12 system because it was 80% R-134. Somehow it made no sense to put what amounted to R-134 refrigerant in an R-12 system.
I'll likely use it down the road on one of my daily drivers when the compressor goes out on it.
I think for now, I'll continue to use R-12 in my Benz. I have a 609 certification, so I can buy it.
I've found that garages charges 3 to 4 times more for R-12 than they pay for it. That's why I have a 609 certification.