I am relatively new in the WPF world and one thing I immediately noticed is how laggy the window content is drawn when you resize a window. For example if you have scrollbars at the window edges those scrollbars will be partly hidden while shrinking and have space between them and the window border when enlarging.
This even happens with an empty WPF project created in Visual Studio. What's even worse is that it also happens with the background and you can see stuff behind the window (other windows, desktop wallpaper, etc.) leak through when enlarging.
At first I thought that it's an ugly limitation of WPF seeing that native or WinForms applications resize just fine (if written properly). But when I look at Expression Blend the window background stays opaque (though the window content still lags behind). What do they do to prevent described problem and are there any ways to improve resizing to more approximate native/WinForm GUIs?