So far, I have been very impressed. The installation is very simple. Once Xobni Insight is installed, the next time you open Outlook will cause it to create an index of your email. On my home system, I have over 14,000 messages from almost 3,000 different senders and it took less than 10 minutes to create the index. During that time, you can still use Outlook since the index is created in the background. It works with mail accounts created using the Outlook Connector as well as Microsoft Exchange accounts.
Once the index has been created, it provides an amazing amount of information, including a search capability that searches your email, contacts, and the web (using Yahoo!). The search is almost instantaneous, much faster than Outlook’s search and more complete. The ability for Xobni Insight to allow you to drill down into conversations, see snippets of entire threads, and see all of the people who are connected to a particular sender is great. The user interface is very simple and easy to navigate, even when you have drilled down several levels.
Overall, Xobni Insight has become an integrated part of my Outlook experience. The beta is still by invitation only, so be sure to sign up.