It depends on what facets you're speaking of, but some parts of Safari are more customizable than equivalent parts of Chrome. Safari still allows you to customize your toolbar, for instance, which unless my memory is failing me was never an option in Chrome.

Of course Firefox beats both Chrome and Safari out in this aspect, but you trade off things like the battery life you mentioned as well as compatibility with OS X services and general native-ness (Firefox has always felt odd and foreign under OS X due to using XUL for its UI). For someone like myself whose extension needs stop at Stylish and a good adblocker, the trade off isn't worth it.