For the past few years, if I've wanted a URL of a page on a site rewritten I've put the rewritten URL into the link on the page.
E.g. If the page is /Product.aspx?filename=ProductA
and it's rewritten to /Product/ProductA.aspx
then I've put the following in my link:
<a href="/Product/ProductA.aspx">...</a>
However, with outbound rules I could just put the links in to the actual file paths, and rewrite with an outbound rule.
Is this a bad method? Would it cost the server unnessacery additional resources?