Bought them through Josh at GetYourWheels. He's all over this thread. I won't post pricing publicly, but if you PM me, I can fill you in a little more.
As far ride quality, it's hard to tell what's attributable to the springs and what's attributable to the wheels because I did them both at the same time. Since most people have said the springs don't affect ride quality much, I'll assume that changes in ride quality are due to the wheels. It's definitely stiffer with a lot less sidewall, but they're way more sticky. Cornering feels solid. It was at first louder, but now that I have about 500 miles on the tires, it's definitely quieted down.
Someone asked about the weight. They're heavy compared to even the OEM 19's. Partly due to the larger wheel and partly to the larger tire. Wheels and tires: they are 6 lbs heavier each wheel in the rear and 3 lbs heavier in the front for each wheel. I weighed them at 56.8 lbs for the rear (20 x 10.5 with 285/30/20) and 52 lb for the front (20 x 9 with 245/35/20). Overall, I've taken an efficiency and acceleration hit of about 11%. All in the name of vanity!