I'm glad to see that the previous reviewer has had nothing but positive experiences with the Microsoft Habu. However, many (including myself) have different stories to tell.
Firstly, I have to say that the feel, design, and performance of the mouse (when it works as it is supposed to) is fantastic. I would not hesitate to give 5 stars on the basis of the good times.
However, I and many others have suffered from problems with the software. Yes, the initial setup can be a pain, but there are plenty of good guides on the internet to advise you on how to set this mouse up from scratch. To me, this is not the issue. The issue is that once set up, this mouse can be very temperamental about working correctly from cold boot. From profiles not loading, to buttons being inoperable, to the O/S - personally, I have tried it on 3 different PC's, using XP Pro and Vista Home Premium, and had problems on each platform.
And therein lies another problem - the hardware is made by Microsoft, the internal lazer and software by Razer. Yet if you go to Razer's support pages, you are told that you need to go to Microsoft for support; yet Microsoft's Product Center does not list it as a supported item. Who supports this product? Who knows!
I cannot recommend this mouse. You may be lucky and get it to work fine, in which case you will have an excellent product. Or you may be unlucky, and join the rest of us with software problems and little to no support. Because ideally the Microsoft Habu is a really good mouse, I have given this 3 stars - it is only the poor software and support which prevents it getting 5.