I spent a couple of hours reading last night after googling acid dip vs media blast. I did not realize how controversial a subject matter it is. I'll see if I can do a quick & dirty summary of what I read.
If chemical strip is done right, many agree it is the best. The body is dipped in acid and/or alkali and then neutralized and immediately e-coated to prevent flash rusting. The key step is neutralizing the last chemical dip, otherwise it will leach out and destroy paint years later. E-coating is a process similar to powder coating. Google it to learn more.
There are many advocates of media blasting. Most agree NOT to use sand, as it is too aggressive and can easily warp thin sheet metal. The downsides of media blasting are that it gets into every nook and cranny and is difficult to remove before painting.
There are upsides and downsides to each. Its sort of pick your poison. Makes me glad I have an Arizona car!