As a side note, if you're concerned about poly count one important trick is to NOT subdivide too early. The whole point of Subdivison surface modeling is that you have a low res cage producing a high res model and subdividing too early can defeat that by raising the poly count too high. However, this should only be a concern when you have huge scenes to deal with, when you're animating (easier to move a low res model than a high res model), or if you're working in the video game industry and have a strict budget on polys for character models.  Just my two bits.