So to me the question whether openbox or fvwm should be used instead of KWin or TWin is just invalid.
No, the question stays unanswerd: Kwin = QT4, TWin = TQt3. So where is the point to switching?
This means the question is what are the advantages of using KWin over TWin. Well I'm not going to repeat what I have written in the past [2].
That does not answer the question, either. In fact it puts KWin on par to fvwm, openbox etc. as far as it's relation to TDE is concerned.
Nik