glue down or staple down?
Given the option, I would go with nail or staple down. I work on a very simple theory, the less of any product containing any type of moisture (glue) you put on wood, the better off you are. I have heard all the great promises and sales pitches on just about every brand of flooring there is, and have seen way to many of them cup after installation.
Our flooring contractor is currently sanding and refinishing an entire house of 3/4 inch pre finished oak that was glued down, with his absolute recomendation that it would not cup. It looked like a back yard deck in less than a month. Fortunately he stood by his word that he would sand and refinish the job if there was any problem, but that did not lessen the aggravation of shuffling a house full of furniture around again, and battling the dust.