Excellent comments Jeni, thanks...

1. Didn;t know that about HTTPS, though makes sense now I think about it
2. Yes, though I need to dig into how much this is supported by tools (such as wget) which people should really be using for grabbing big stuff (or large numbers of files)
3. I do! Always enable this in FF :) Again, need to understand whether this exists in non-browser tools
4. Excellent idea, or in HTTP transaction time vs download time. I'll add an issue for this. Would be nice to get some real figures in here, though dunno if simulating that right now is top priority vs the rest of the text.

Are you happy with this draft text? Do my claims stand up? If so would you like to merge the PR?