Mercedes-Benz was, arguably, the first premium brand to come up with the coupe-sedan niche when it introduced the first-generation CLS Class some 15 years ago and now you can get what is effectively an enlarged AMG-GT that follows the ethos of the CLS but is a lot more sporty. That’s a tasty proposition but how much of the Mercedes-AMG GT53 can you really fall in love with, beyond all the figures?