When you read the pages for each product in 
you will see very similar characteristics. The real difference is in the level of solids content for each.
S-B-S Sealer is the lowest solids level of the three. It is used on porous surfaces when little or no gloss is desired, but is designed for dense, low absorption surfaces where you need maximum penetration. A higher solids product will tend to penetrate less and leave more solids on top and that is what creates the gloss.
"Porous Stone Sealer" is the mid-range of solids content.
"Mexiglaze" is the highest level of solids content.
One of the considerations is that a porous surface will absorb more sealer of a lower solids content, therefore, the higher the solids content - the fewer gallons required. However, it is best to not use a solids content level so high that it does not penetrate down into the surfacing. You can order samples 
to help decide which is best for your goals.
If you start with one of these sealers and decide the solids level is too high or too low, you can:
- Solids level too high: Remove the gloss created with the higher solids level sealer with lacquer thinner and then continue with one of the other of these three sealers.
- Solids level too low: start over with the next higher solids level. They are the same formula family and the new will bond with the old.