You wont regret it Gongfisher, my usual mechanic mentioned that he could eat his dinner off the underside of my truck and that's several months and a few puddles later.

Letsgetem, they use garnet powder these days. What I will say is that despite their (Autoblast's) best efforts to clean the vehicle inside and out, the garnet residue will work its way into every nook and cranny. Be especially careful to clean around the fuel filler area as you wouldn't want that stuff going into your tank. I also changed my air filter out even though they blanked the snorkel. Just in case. 

But top notch job.

Cost was $2600, 3 years ago.

I liked their service. They dont do any panel removal etc.

I liked the sound of what they did - particularly sand blasting (much more thorough removal of rust and old coating, than brushing or grinding). 

Theoretically, if its completely free of rust and has strong coating, it should not rust for many years. 

However, I did make poor decisions, when I found rust right through an area of the floor (caused by my shoes dripping water down when I was trout fishing and sea fishing). I opted for a less-than- perfect job to grind out rust and then apply paint. Not surprisingly, it continued rusting. As a should have known (and been taught many times in the past) - IF THERES ANY RUST REMAING IT WILL CONTINUE TO RUST,  EVEN UNDER PAINT! TO STOP RUST, MUST EITHER REMOVE ALL RUST, OR CUT OUT THE RUSTING SECTION AND REPLACE. I subsequently had the rusting floor cut out and replaced. 

And it occurs to me, that I dont know what is happening inside the chassis members; hopefully rust free. Possibly that could be treated by injecting something inside, eg Tectyl. But I assume that would only work if there is no rust underneath.  

Autoblast on Nth Shore. I had mild surface rust (beach launching) despite cleaning under the truck each and every time. For me, peace of mind outweighs the hefty-ish investment. 

Part of the problem is you are looking at the outside of the steel sections. Easier to get at than the insides. If you are really worried, sell it? Move on.