SilverEfex is a fun application to work with. I found its functionality surprisingly good. I was using the LR plugin version, but I assume other versions have similar functionality.
One comment about the image itself: I like the overall composition, but the tree in the foreground serves no purpose to my mind, other than getting in the way of the rest of the image. This is probably because there's very little tonal separation between the tree and the landscape. I do, however, like the composition of the landscape behind the tree. I would suggest either eliminating it or giving it less real estate in the image.