I've had 1 car dipped (It was actually an alkaline bath not acid), one bead blasted and a few stripped by sanding and paint stripper. I would never use the later method again - too messy and labour intensive.
The dipping does a more thorough job - removing old plastic filler, body deadener and cleaning up the rust. It even leaves a film on the surface that protects the car from environmental moisture for a few weeks if left undisturbed. My S was done about 15 years ago and there's still no signs of rust or corroded joints, but it was treated with fishoil in all the box sections before painting. Bead blasting is fine removing most paints, but doesn't remove bitumous paint or bodydeadener, nor does it get into every nook and cranny. One pain in the butt aspect of bead blasting is trying to remove all the beads that worked their way into the box sections and float out whenever a spray gun comes near. You can spend weeks vacuuming and airblasting the box sections to get them clear.
Both cost similar $ - you make your choice.
