Which makes for a better performing floor and WHY?????

I have heard installers love staples/nails as they are easy and cheap. But that does not make for a better performing floor. I have heard staples and nails cause floor squeek too.

I have heard that glue provides a better bond, less squeek, and can move better with the floors natural expansion is this true?

We are talking a thin solid not 3/4 being glued onto ply.

Mechanical fasteners (nails, staples, cleats, etc.) are permanent and will last indefinitely. Adhesives may last a long time but who really knows. I've seen 30 year old floors fail because the adhesive broke down over time or became brittle. That's the older adhesives. The newer ones haven't been around long enough to judge longevity. As far as right now, nothing more solid then a very well glued floor, except MY very well nailed floors.