I'll tell you what I know about Alsa. It is pretty expensive. A lot of people say the spray cans do not give a great finish. Nobody knows how durable it is, but it has to be clearcoated, or it'll rub off. And most clear paint will yellow considerably when exposed to high temperatures. There is really no info out there about it's durability. As one actual user said, "I would say Killer Chrome in the aerosol can is a very expensive product which provides very mediocre results."
Here is info from some Alsa users: Alsa "Killer Chrome" product review - Hot Rod Forum : Hotrodders Bulletin Board Refinishing With Alsa Corp Chrome Spray
I'd spend my money on the powdercoating that looks almost like polished aluminum. Leanna calls it "Super Chrome". She does super work. http://www.phoenixspecialtycoatings.com/index.html