Here's a spot where the stain didn't take. There might have been something on the concrete that made it non-porous. Now that I see it in the picture, it looks sort of like an animal laid down, died, and decomposed right there. But, of course, that didn't happen.
The instructions say that after the floors are stained and cleaned, they will look dull, but don't worry, when the sealer is applied, it will bring out all the rich color, etc. What the instructions don't tell you is that the scrub brush and wet/dry vac that they instruct you to use to clean the floor will leave streaks. These streaks will not go away no matter how much rubbing and vacuuming you do.
More streaks over an otherwise nice marble looking pattern. There are a lot of cracks in the concrete that I didn't realize were there until now. I can only hope that the streaks will go away when the glossy sealer dries.
When I checked the floor this morning, it still had a residue, so I scrub-swept it with the push broom and vacuumed it with the wet/dry vac. Then I appled the sealer with a roller on a long handle.
I am completely exhausted and sore all over, but...I'm done. And I saved a couple of thousand dollars. Oh, there is no possibility of putting a checkerboard pattern on it unless I paint it, which I don't want to do. I found out the concrete won't take another stain.