We try to stick with one brand as much as possible to allow for sharing batteries, chargers, and tools between installers as needed so we generally use Makita 18V. But annoyingly, the Milwaukee cordless finish nailer (both 15ga and 18ga) is far superior to the Makita version so we have those as well. Having the cordless nailers has allowed us to virtually eliminate the need for air compressors on the job site which is great because they are heavy and seem to take a lot of abuse when moving from site to site. (anybody want to buy a well-used air compressor? :-)