Speed on MacOSX
FYI: I finished my build on MacOSX from source. The good news is that the build was very very clean and used -O3 optimization as you said. The bad news is that the slow speed is still there. My guess is that Qt on Mac OSX is simply not being optimized or is just darn slow. Because of the impact of larger html files and given how lightening fast Tidy is, my guess is the problem is related to the Qt html widget and/or redrawing. If that is the case, unless there is some way to split the large html books into smaller pieces automatically (some type of chapter by chapter auto splitting? - or a really smart dom parsing routine) and then assigning a different Qt html widget for each segment, I am not sure what is anything can be done.
Since X11 is now integrated right into Mac OS X (not an add-on anymore since Mac OS X 10.5), I tried to find a version of qt-x11 to rebuild against just to see how it compares for speed to native Qt but qt-x11 for Mac OS X doesn't seem to exist anyplace on the Qt (nokia) site anymore.
The only other thing is building Qt from source itself against X11 on Mac OS X just to see? If I get some free time I will do that.
I also have access to a Linux box (still running Fedora 8 - so no Qt - 4.5.3 pieces installed) that once I update to Fedora 11 or 12, I will try it for comparison speed purposes.
Hope this info is useful. Please let me know if there is anything I can test or do to help.