I feel like this is almost a non issue unless you're running a site that absolutely needs to run everywhere since the last browsers that shipped without gzip support were released in what, 1998? A significant portion of your users (according to O'Reilly's 2009 _Even Faster Websites_, around 15%) don't say they can support gzip even though they can. Just ignoring Accept-Encoding headers and serving only gzipped content is probably good enough for 99% of people and likely gives you slightly better overall performance on average than actually respecting whatever the request headers say.