Recommended purchase Audi A6 or BMW 5 Series GT

Hello people I absolutely need a purchase advice!!! I’m currently driving a Mercedes Benz E 320 CDI built in 2007 (Facelift) Limo. I’m actually fully satisfied with the car. However, I have family growth and need a bigger car. Of course also a diesel My choice has actually already been limited to the 5 GT and Audi A6 s line Kombi. However, I can’t decide and ask for your help. I don’t really want the 5 Touring. In my opinion, Daimler’s combo is not beautiful at all. Maybe someone has experience with both models and can make me a purchase recommendation. Thanks already PS: Which motorization would you recommend with the A6 s line combo