Ok, a far far away insight here.
Done business with them a lot, and probably will do. I've got almost all the time an order open with them. My distance and being a non-US customer makes things a lot messier. Practically there are no chances to return anything as it just is not worth it, and the borders (the Customs etc) make it far more difficult anyway.
They make mistakes as all the people do, but they also correct the mistakes. For example, one wheel in a Magnum500 wheel set was bad, not very straight and worth only for a spare wheel in the trunk. They sent me a new one for free, and I can use the bad one for hanging garden hoses etc.
Products; they are pretty much the same quality as everybody's. Some of the parts are the same brands as everybody sells. Of those hundreds of items I've purchased from Cal I have had only two very bad quality items.