The op asked which style of blasting... I've only ever sandblasted and the only negative to me is the time it takes to get all the sand out of the rail, seams, rockers etc. It's not as bad when the car is on a rotiserrie, but still takes a lot of time. I'm working on a car now that when I removed the floors there was an inch of sand in areas from being blasted before and not cleaned correctly.

As far as dipping since it's being discussed... wouldn't do it if it was free. The less chemicals used the better.