Is that why the capability of a user's video card had an appreciable impact on the performance of a WPF-based app that's little more than a text viewer and editor, at least as of 2009 (see http://community.logos.com/forums/t/6200.aspx)? Is the WPF renderer still suboptimal on today's graphics hardware? I'm thinking in particular of Intel's integrated graphics starting with Sandy Bridge. And does Direct2D have a better software fallback?