Product finder is a nice improvement, but doesn't do what I want. I also think it's overly technical for a lot of users.
Take a look at the search on ModCloth: http://www.modcloth.com/shop/search?keyword=shoes&category=all-categories&commit=Search
You start with a keyword, then you can drill down by category and by product attribute (size, color, etc). It's like a combination of the WooCommerce search feature and the Ajax layered navigation.