My basic understanding of it is (I could be wrong here) is that the P94 brush system brushes are squarer opposed to normal stand up brushes (like your Reedy ones) which are more rectangular. Im pretty sure all Trinity mods from the P94 onwards use the P94 brush system, including D6's, Cobalt, the new Epic Shock motors etc.
The brushes that came in the Cobalt are still P94 Brushes, but are made from the new XXX compund which is meant to last for ages, be easier on the comm etc. Which from my experiences they do seem to be a significant improvement over the Standard compound, I ran one set of brushes at the worlds through practice, qualifying and finals.
To make it more confusing, there is a new hexagonal shaped P94 brush available.....