I have had one on my car since they first came out in Febuary. It is a very worthwhile upgrade, but I definitely recommend the energy suspension bushings that I have bosted about in several other posts. They really make a difference.
As promised, I installed the IPD sway bar on my 2011 XC70 T6. It was an easy installation, took about 30 minutes, and wow what a difference. When the XC70 would go around a turn, the back would almost lift up and it just felt like a wagon. Now it is very tight around turns, feels more like my S60 RD than a wagon now. For $260, it was a great improvement and an easy upgrade. If you need any other info, please don't hesitate to ask.