Wow, this thread has gone down some roads......looks like we are down to splitting hairs. Seems the conclusion would be for a driver or budget build up by garage guys that are not too particular, POR will get 'er done. For a show car or proper rebuild by a detail oriented builder, rust removal is best.
Jessie, I am sure you have had good results with POR as have many other respected members on this board, but pros like MartinSr and BarryK are never going to endorse the stuff......ever. As a matter of fact I am a backyard junk builder and I would never use it either(At least I have not thus far), but each to his own.