I use Silver Efex in the lab fairly often and find it a great addition to the toolbox.
"Can anyone tell me how they developed this plug-in? Did they hold a seance and contact Ansel Adams and Edward Weston? I don't know. I do know that Nik Silver Efex Pro is as good as gold. Even somebody like me can achieve fantastic results in just seconds. You may begin to smell the chemicals after looking at your own results." - Craig Wolf