Yes, it does take a bit of study to understand the changes in Vista. However, when I installed it on my dual processor computer, the performance improved very dramatically.
I've been running with an ADS using Vista clients and have no problems.
I'm using dual monitors ... no problem.
I did switch to Microsoft's Live One Care for anti-virus, firewall, and other protection. The price is better then the competitors offer, the performance of my computer is greatly improved, I have no conflicts with applications I develop, and I've had absolutely no intrusion of viruses, worms, etc.
The Microsoft model for computing's future is driven by those who use the systems in their industries, not by the developers. So there are changes coming that may require us to learn more, but I have seen many people very pleased with the capabilities of that new direction. When the 64 bit server products are released in February we should see an even greater performance boost for Vista.
Yes, there are some things I would love to have differently. I find it interesting that I can sync my handheld to Outlook, but I can't sync two copies of Outlook ( notebook and desktop ) with an easy sync application from Microsoft. Networking is a bit more challenging, but when its set right, it is safer and works fine.
If you don't like the security changes, remember that these are the result of hackers causing billions of dollars of damage to computers throughout the world. These same people would be happy to steal your software if they could gain a benefit, or crash it just for the fun of it. Maybe with more honesty, we could require less security, and easier operating systems.
I'll get off my soapbox now ...