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

Hey All

I've got most of the drivetrain pulled out of my car and figured this would be a good time to hit the underside of the car with some anti-rust stuff.

The car is in really good shape with just a light layer of slightly flakey rust on the floorpan, etc. It doesn't need to be repaired anywhere.

What I've done in the past (on newer cars) was just to hit the underside with some Rustoleum hammered finish paint. Both to protect from rust, but also to cut down on falling rusty flakes when I'm working on it. I greatly prefer silver to black because it helps make for a brighter work area under the car.

I don't really know how well the Rustoleum protects against rust, but my cars are sunny day drivers anyway. the only time it would conceivably get rained on would be a surprise shower, or something like that on the way too/from the track on a trailer.

Anyways, since this is an older car, and I dont want it to get bad, I was thinking about doing the POR-15 or something like it.

Long story short, does anyone on here recommend it, or have any warnings about it?

thanks!

Steve