Almost all the common 'stains' are pigment stains that contain pigment particles similar to paint.

Darker is harder to handle and make look good.

That is what I would think - darker is easier to mess up and more likely to require call backs to fix issues. We are going with a dark stain though.

After just coming through a hardwood floor stain debacle in our house, I would make sure you get good samples. Our builder only provided a sample about 3 inches x 8 inches on one place on our floors. We later learned that large sample boards with your type of wood & scraping, if any should have been the norm. Or, we should have asked for larger samples on our actual floors.

Our builder did mention that in his own house, he has Ebony stained floors and there is a lot of variation. He says some planks of wood are not dark at all.

You may just want to be prepared. The alternatives after the entire house is stained are not great.

Thanks everyone for the replies. Have any of you had the floor finishers try to charge you more depending on whether you are using a very dark stain or not?