When you use GZip, all your "keys" are essentially free except for one copy. So your gzipped vs gzipped optimized should be the zipped sizes of all the keys, which you're going to send over the wire in one way or another. In other words, the optimized version has no benefit over the version with keys when gzipped.
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When you use GZip, all your "keys" are essentially free except for one copy. So your gzipped vs gzipped optimized should be the zipped sizes of all the keys, which you're going to send over the wire in one way or another. In other words, the optimized version has no benefit over the version with keys when gzipped.