Need opinions on anti-rust paint (POR15, Rust Bullet, etc)

I've used both POR-15, to coat a gas tank and the Eastwood Rust Inhibitor paint (can't remember the name - ahh, yes, it's called Rust Encapsulator) on a chassis. The POR-15 has a much tougher finish after it dries. The Eastwood stuff goes on smooth but doesn't leave a hard finish. It's easily scratched.