I might add thextra thigh extension only applies to 2016 and upTirgoman is totally correct. I tried the sport and AMG (recaro) seats. The sport seats were softer and less restrictive but hit my back/sides in the wrong places. I just couldn't find that sweet spot. I went with the AMG (recaro) ones and glad I did. So, it's totally a matter of personal taste and fit.Big difference between the std, the sport and the AMG Performance Seats (Recaros), everyone has a different taste so try before you buy. Personally I have the AMG Performance Seats (Recaros) and think they're great.
Another nice thing about the sport seats (not mentioned in this thread) is the thigh extension. The AMG Recaros don't have the thigh extension.