I reviewed QTP as a Java Test application and found it to be adequate, but with a bid red caveat!
Last shop I was at we had a stand alone Java swing app
Tool eval was roughly two years ago
Short version of results
Mercury - Tools did inadequate job of harnesssing GUI
Rational - To green (no DB support)
Compuware - acceptable
SilkTest - our choice we reaffirmed by oppinions of others, and I would use it again...
Note: This was a standalone swing app, NOT hosted in a browser