How usable is a document which uses <ins> and <del>, compared to seeing the deltas in a two-pane split-screen diff viewer?
Although a command-line diff tool will show its output as one diff after another (in a single vertical column / console window), all the GUI diff tools that I know of tend to show diffs in a two-pane, split-screen UI.
I'd like it if <ins> and <del> were usable but it worries me that, instead, two-pane split-screen diff viewers seem to be the norm.
Secondly, have you seen any sites or software which use the <ins> and <del> elements to show revisions, and if so would you please point them out to me? I'd like to see examples of their being used (in order to make a subjective opinion of how usable they are).
Trac uses this for example on its diff pages and does that even in a two-pane view. You can see an example here.