Agreed also with Node.js, and we didn't even see meaningful improvements in data size for our usecase without double encoding. The size of fairly repeated data with JSON+GZIP was on the same order of magnitude as the raw data with protobuffers. To be fair the protobuffers included some unwanted fields, but it was expensive enough decoding them, what were we going to do decode AND encode them again? No way, decode, slice in JS and send the JSON, with GZIP it was the same size.