To be honest I don't care if the 5M is more fashionable or more new than the C4.2.
They sure are similar in overall geometry and layout, and undoubtedly the 5M is born from the Centro car.
I have the C4.2 and think is a great car.. When I will match the driving ability of big guns like the Ryans I will probably feel the need for something better.
(read: I would probably never feel the difference)..