We did some test apps during the alpha/beta testers program and purchased one license for "recreational use". We created some half-production use web server apps with it, but it was mostly used to play with. Nothing with GUI, though, only server stuff.
Now that I come to think of it, there was something funny with the UI code. Did it hardlink in QT? I think it did. Borland (or whatever they were called at the time) coughed up some dough and got a license where they could link in QT libraries in the executables. It was portable, but probably anything but quick.