Sound, by the way, worked right away on my system. No post-configuration had to be done. Installing additional applications MS Office installs without any problems. It runs very well too - no crashes so far. I've been using it for the past two weeks now just to test performance and stability, and it really works great.
Performance is top notch.
Better than I would have ever expected. Furthermore, I've tried out a few other Windows apps such as WinZip, mIRC, and ACDSee. Everything runs smoothly. I really like Win4Lin. For optimum performance I would personally suggest 64 MB RAM, if you have more than 128 MB RAM in your machine.