Tkinter and Swing performance

[C.L]

Has anyone done a large GUI app with Python and TKinter?  So far I have
found that:
1. TKinter is faster (more responsive) than Java's Swing library
2. Tkinter apps use less memory than a similar sized Swing app
3. I find Tkinter is easier to work with than Swing

Does Tkinter's performance slow down when an app gets large enough?  So far,
I am thinking building my client's GUI's in TKinter and Python is the way to
go, and to use Java on the backend where needed.  I know that Java has never
been a real good candidate for the client side apps, but now even with
trying my apps on the new JDK 1.4 Beta which is supposed to handle Swing
more efficiently, there doesn't seem to be any noticeable difference, and
the JDK is now 48 meg in size!

Any advice on medium to large Tkinter apps?  Problems, issues?

Thanks.