[KevinH]

FWIW, I do understand about dropping the alpha channel, cropping, and restricting the number of colours and that it can end up being quite lossy. I understand that keeping high resolution images as originals is a smart idea and not using anything lossy until the final step makes great sense. And all of this makes even greater sense for print.

It is just that image file sizes on the web and in browsers trumps all of that for me as long as at normal display sizes no big differences are noticeable. Again, speed of loading, caching, reload, memory footprint, disk footprint, download size, bandwidth used all are greatly improved. Which is probably why Photoshop has a "save for the web" setting to begin with.

If this manual was destined for print, then I would agree with you. As it stands this user-guide will probably be viewed using Sigil and PageEdit in most cases as people play to learn and for that role, I think these images work well.