Being a relativity new comer to AMG, you can only judge as you find. My 2014 S212 is rattle free, has decent materials and every thing works apart from the auto load cover. Bit harsh to say the seats are grandad like, I mean they not covered in velour with pipe baccy holes !
I had the opportunity whilst solo the other day to try it in 'manual' mode and swiftly came to the conclusion that you do not need any more than the stock motor for road use. Not being a fan of touch screens the buttons and switches appealed to the analogue side of me.