Yes, the glass beading removed all the paint and "highlighted" the small rust holes around my rear window by removing the weak metal around the holes. It also left most of the heavier bondo intact so I could see where the previous damage was.

I had no need for more agressive blasing as those few small holes are my only rust issue - this being a car that spent it's entire life in Southern California. The floor pans were beautiful as were all the suspension components. I just wire brushed the crud and undercoating off the bottom of my floor pans and repainted them. It may be hard to understand how clean an old car can be from So Cal or Arizona.

I replaced the subframe on my car because it was badly caved in from below due to bottoming out - not because of rust issues. The bolt-on subframe is one of the reasons I like working on these cars. However, it you have rust issues, you may find out like others that your subframe bolts are so rusted into the cage nuts under the floor that the cages break loose. My subframe bolts all came out pretty easily after just treating them for several weeks with PB Blaster.