From my perspective I think the problem for Qt people like me is that there was no compelling reason for Trolltech to "break" code like QListview. Qt4 QListView could have been made backward compatible with Qt3 QListView w/o disrupting the MVC approach used in the other classes.

Instead Qt 4 QListView is now a single column list. I have approximately a hundred thousand lines of Qt 3 code that will take months to convert to Qt 4. I anticipate that the QListView issue will be a large component of that conversion.

Also, I don't want to have to distribute the Qt3 support lib (2 meg) with all of my applications.

I'm sure that Qt 4 is a much improved product, however, IMO, Trolltech could have done a better job in mitigating source code incompatabilties.

Just my 2 cents.