i currently use aero p1 pads and in my opinion they are the best light pads available. they are extremely comfortable (once you get used to them as sometimes it takes a couple of net sessions to adapt to them) and they are really protective. faced 70mph and never felt a thing.
i have seen the morrant ones and have to give them credit, they are so so so light, lighter than p1's by quite a bit, however i would have a problem with the surface on them. it seems they would get dirty quickly and stay dirty unlike the aero's which you can just wipe clean, the morrants have a cloth fronting where as the aeros have a 'plasticy' coating.
i've never picked up up or used the CA ones so it would be unfair to comment on them.
i would sell my p1's as i have 2 pairs if your interested