Por15 is my favorite. I am not too fond of Eastwood's rust encapsulator because it lifted, or caused other paints to lift when you topcoated. Rust bullet was just terrible, rust came back in 6 months. POR 15 seems to lay down and protect the best and takes a topcoat nicely. (Just lighly mist it with some spray paint when its just barely sticky-3to4hours later, then allow to dry. Topcoat over the misted areas once its dry and you will get great adhesion.)
Do not clean with solvents, it makes the por pock. Clean well with a simple green type degreaser then use the POR15. I dont use their prep prpducts. POR directly on the metal, and have had great luck.
[This message has been edited by smartaxel (edited 06-02-2014).]