When the framing and sheetrock were installed all the cinder block was quad coated (four layers) with 'Dry Lock'.

It should depend on the location (better locations would have lower IRRs) and the amount of risk in the deal (major rehabs would have higher risk and thus higher IRR than a coat of paint flip).

Some folks could use some thicker skin, imo.

It is an older home in an older neighborhood, so I think other houses probably also have thicker thresholds in places too.I could save some money and lessen the height difference by putting in an engineered wood floor, but then the finish won't match with the rest of the house (not to mention I don't think it is as good of a product).

I don't know if I'd want to risk doing tile again with smaller or thicker tiles, and later be kicking myself if the tiles or grout lines started cracking again.

Modern materials and coatings do a great job from having a dog scratch up a floor however at the same time you don't know if they're going to chew up the cabinets or some nice molding around a door.

The part that goes in the toilet has a rubber coating on it so that you don't chip the porcelain when you are working it.

Dearest Trina, Not only do we need skin in the game in some fashion, we also need much thicker skin. 

I'm getting tired of being told, "yeah, it covers great" and then finding after 2 coats it still looks like crap.

They will need three coats of prime.