It's more than important in Symfony2, it's actually the only way to cache data (beside of course memcache etc). And even if you don't have a reverse proxy like

It's more than important in Symfony2, it's actually the only way to cache data (beside of course memcache etc). And even if you don't have a reverse proxy like Varnish to fully leverage HTTP caching, there is a built-in reverse proxy.