There are some very good comparison testing going on out on the net. The links below offer some great information for those wondering about how Amsoil MPHD stands up to the other metal protectors out there.
That being said, the second link below, the winner was not tested against Amsoil so I just ordered one can each of the Amsoil MPHD and ACF-50 for my own testing (will post more later when the products get here.)
The first thing I noticed was the pricing. Without shipping the Amsoil is $8.20 per can retail while the ACF-50 is $12.19 per can. If purchasing a case of 12 the cost retail is $146.28 shipped and he Retail cost of the Amsoil is $115.45 shipped and I can save you more than that with wholesale pricing. For that kind of price difference, I would expect the ACF-50 to last a LOT longer than the Amsoil, but we will see.
Clear Undercoat Recommendations
Corrosion Protection Comparison Testing (Does not include Amsoil)