By the way, — signing is not equal to "null encryption". Signing can be done in advance, once. Signed data can be served via sendfile(). It does not incur CPU overhead on each request. Signing does not require communicating with untrusted parties using vulnerable SSL libraries (which can compromise your entire server).

As we speak, your SSL connection may be tampered with. Someone may be using a heardbleed-like vulnerability in the server or your browser (or both). You won't know about this, because you aren't personally auditing the binary data, that goes in and out of wire… Humorously enough, one needs to actively MITM and record connections to audit them. Plaintext data is easier to audit and reason about.