i go @import every time. it forces you to structure your html document properly and like, the stick says, also avoids any hassles with getting nn4 to represent your site properly.
maybe have a look at this:
www.trp.co.uk/trplast/
its a basic example of @import being used to completely disregard nn4 but the html markup still allows the viewer to make sense of the contents of the page. check it in ie5+ and nn4. it'll might help show you the why and how's. it also works wonders for search engines.