Pros: The birds like sitting on it when it isn't turning.
Cons: low output, poor customer service, broken
I purchased a Windspire a few years ago. I've never been happy with the power output. Since then I have been through 2 inverters and due to a faulty shorting clip, the unit sheered off in high winds and the top had to be replaced. The last episode was once again after some heavy winds and the brake wouldn't kick off. After waiting several months for a replacement inverter, I installed it and had a great run of about 3 months before another windy day with high winds caused the brake to kick in and it never came off again. I've been trying to call Windspire, but apparently no one actually works there as I keep getting answering machines and no call backs.
If you don't mind poor tech support, a company that is in it just for your money, and a pretty bird perch, then go ahead and buy one. Otherwise, STAY AWAY! We'll see if my lawyer can handle the company better.