Conclusion
Overall, DisplayLink's USB-to-DVI adapter is a mixed blessing. On one hand, the device has undeniable potential, and it works fine in Windows XP provided your monitor's resolution isn't too high. On the other hand, its poor performance in Vista is a pretty big caveat and could seriously impede its usefulness on most newer PCs. DisplayLink's spring release time frame for its driver update means a speedier driver may not be available until June, which is a pretty long time to wait.

I would be more inclined to forgive poor Vista performance if this were February 2007. However, Vista has been shipping on most new PCs for over a year now, and the release-to-manufacturing version became available all the way back in November 2006. DisplayLink may have limited resources to spend on driver development, and the limitations of the USB interface could be more to blame than lackluster drivers, but incomplete Vista support today is nonetheless hard to swallow—especially for a product with a $150 price tag.

Folks seriously considering this adapter will need to evaluate carefully whether their hardware, operating system, and usage patterns are suited to it—and whether tossing in a cheaper PCI or PCIe x1 video card might not be a simpler alternative. If you're a laptop user who still runs Windows XP, or if you have a Vista laptop and only need an extra display for office work, then the adapter is a decent choice. However, there are compromises in both cases, and DisplayLink's product really can't be considered a full-featured replacement for a proper DVI output—at least not yet.