[bandie91]

a drawback of relying on ETag is that if a page is visited frequently, then the cache validation "If-None-Match" request still being sent and takes bw+latency+computation+etc and I suspect that if the connection is broken or status 503/504 is responded, then neither the cached page is shown. my understanding is that he whant to refresh the page only if it's known to be changed and always use the cached version otherwise.