So here is the project:
1. To be installed: 1000 sqft of prefinished, 3/4" X 3 1/4" hard maple, natural w/ satin finish
2. Subfloor: 2 layers of 1/2" CDX or better plywood, glued and screwed together
3. Climate: upper Midwest, late fall project.

What would your preference be, nails or staples? I plan to buy a stanley bostitch pneumatic MIII nailer or stapler. I have heard a few opinions each way. It looks like there are more used (ebay, etc) staplers than nailers available. We have used a manual clear nailer (hard work) on two previous projects, but have no experience with staplers.

Any suggestions are much appreciated.

I use a pneumatic stapler. The boards are nearly impossible to pull out when installed. It provides more holding force than cleats.

Thanks kls

what about if you mis-staple or screw one up and need to pull it out?
don't you want the floor to allow for some movement (expansion/ contraction)

anybody else have input?

I should have said by hand they are easily pulled up with a pry-bar whereas a board installed with cleats can be removed by a strong mans hand. Most companies have a nail set guide that allows for wood movement. The staples will allow movement but too many in one board can cause problems.

Thanks for the clarification, i think I will go with the staples then.

no experience, no man. You can use staplers very easily as you do use you nailer. If there is still some problem while installing or letting it work with your projects read the manual guidance can help you in order to use . . .!