Most brands seem to market a standard and premium version of their carbon road bikes, same geometry different carbon. Toray 800 versus 600 maybe but like steel it wont be all the higher grade carbon itll just be key areas which are often undefined.
So you have Bianchi Sempre and Oltre, TCR advanced and composite. Tarmac and Tarmac SL etc.
Many of the no brand frames seem to claim to be made of the higher grade carbon. Brands would say you are loosing out on some R&D but how much that R&D adds in terms of improved function is up for debate and I suspect many brands are just marketing department paying the eastern manufacturers to do the design and either paying for sole rights or a generic frame.
In my experience the difference between an average aluminum frame and just about any carbon frame is night and day, were as Im not able to feel that much difference between the different carbon frames in terms of say stiffness or vertical compliance.
I do still however like a brand, some have specific fetures, it has to motivate you to ride, look nice and generally have the feel good factor.
I own a Bianchi but only because it was on offer, when i last tested a load of carbon bikes the Giant TCR composite was my favourite, Geometry suited me, shaping looked well thought out, finish good and it came with some good parts for the price.