I agree ... mostly. One of the examples was bytes downloaded. The reason I, and I suspect other users, interpret that as % downloaded is that in most interface

I agree ... mostly. One of the examples was bytes downloaded. The reason I, and I suspect other users, interpret that as % downloaded is that in most interfaces (e.g., iTunes, Firefox, Safari), below the download progress bar, it says "XK of YK". (There is also an estimated time remaining, but it's typically not on the left side.) In other cases (installs), yes it makes sense that the simplest interpretation is time, because that's what we care about when installing: how long until we can use the new shiny widget.