Neither Komodo nor BlackAdder is quite ready. Komodo needs to get snappier, and a lot more stable. Curiously, though BlackAdder is also in beta, it isn't slow. A bit unstable, though not as flaky as Komodo. The beta-ness of BlackAdder is more in its lack of features and polish. Both IDEs show promise, however, even though their respective strengths are in quite different areas.
Komodo offers a multi-language support unparalleled outside Emacs, in a modern package. Planned enhancements include source code control-system integration, multi-language object browsers, and support for even more languages.
BlackAdder is more clearly focused. It's an IDE for the rapid development of GUI prototypes or GUI applications. The resultant applications can easily be deployed on Windows or UNIX/X11, or moved to C++. BlackAdder should be the first choice for companies that want to develop an application for both Linux and Windows. The editor is as comfortable as they come, and the debugger is useful enough. It's in GUI development that BlackAdder is strongest.