As another random anecdote from another random developer, I find the site's content far outshines any purported credibility loss - which just seems like a very silly argument to make.
Perf is not important for a dev resource. If a dev had spent a ton of time optimising that they'd have wasted their time. Why does wasting their time make them more credible?
* HTML compressed (gzipped tar file) - with one web page per node.
* Info document (gzipped tar file).
* ASCII text compressed (gzipped).
* TeX dvi file (gzipped).
* PDF file.
* Texinfo source (gzipped tar file).
If the one big file (great for grepping) was too confusing, you probably want to opt for HTML, with one file per node. For example, the Sockets/Local Namespace page for glibc: [0]