Bumping - we move into new house with river white granite in a few days and I am trying to figure out which sealer to apply.

Bump... I have Crema Astoria and am curious about what everyone thinks. How many coats of 511 would you apply?

While sealing stone surfaces is a professional activity or job I think it is better accomplished by the homeowner. I’ll explain why.
I try to always explain to customers they should think of sealing in terms of applications. Sealers can take up to 24 hours and more to cure. If you consider the average sealer product is 90% or more carrier (water or solvents that the sealer resin is diluted into).
Most sealers have less than 10% resins, the chemical that solidifies in the pores or open spaces of the stone.
The carrier has to evaporate and the resins need to solidify. Some sealers will even take longer to cure.
With this knowledge applying and understanding the sealer will make more sense. So applying multiple coats of sealer in the same time period or even day could be considered one application.
To clarify the application process, Sealing could be done in this manner.
Taking care to protect your cabinets and floors and working in manageable sections(3-4 feet wide)
Apply the sealer to the first area and keep it wet(with more sealer) letting it load into the stone for 10-15 minutes.
Then remove it all by wiping it away and buffing the surface dry. That's the crux of the process making sure all sealer that isn't absorbed is removed from the surface.
Sealers are impregnating they live below the surface.
Then move on to the next section overlapping the first and repeat the process until the entire surface is done.
Check to make sure there aren't any sealer residues left on the surface. If your surface has turned darker that is a sign that the sealer has penetrated the surface. It will return to its original color. If you think the surface can take more sealer repeat the process. Then wait 24 hours and do the water test. See what you get if water can get though you will need another application. Repeat the process and test again.
I hope that gives you a better understanding of the sealing process.
As far as using porous plus the difference is only the dilution-there is a higher concentration of resins in the porous plus. Quite simply the comparison is that you will need more applications of the impregnator sealer product than of the porous plus product.
As far as the DuPont bullet proof I don't think it is any better than the miracle except for the name bulletproof which is probably why it sells so well.
While I do think homeowners will do a better job sealing I want to list the performances of a impregnating sealer.
1) To temporarily inhibit the intrusion of staining agents into the surface of the stone.
End of performances!
I am in residences everyday and don't see all that much staining on stone. When we do, most staining can be removed. Just like you mentioned we have had people call us and tell us about new stains, then call back days later and say they disappeared
Rust stains are an issue that we see more often than other types of staining. Stones that contain iron content in their mineral composition can oxidize and yellow. When it does happen it is tough to resolve.
Hope this helps regarding sealing of stones.

On another site, a stone fabricator sealed and stained several stones. Tenax did the best job. It's not the most expensive and a pint is available online. Try DeFusco.