[arch-general] Pacman/pactree

Dear list, I did some spring home cleaning today among my installed packages. I wanted to remove one package, but be sure first to know which packages were depending on the one I wanted to remove. I then went to the pacman wiki, and read the following command would do the job : $whoneeds packagename. A quick tour on #archlinux IRC gave me this anser for same result: $pactree -r packagename. Is there any reason to use "whoneeds" command more than "pactree -r" ? As pactree is already installed, I do not see the need to install a new package for same result. Not a big deal, but just curiousity.