I have been using Bilstiens for the last 30 years and they have worked great. They even warrantied shocks that was over 10 years old. When on a budget I have used Bilstiens on the front and whatever I could find cheapest on the back. My W123 has Bilstiens Front and and Monroes in the back. My other brand SCCA car had Bilstien Sports front and BOGE rears and I won too many SCCA events with that set up and the Bilstien shocks are still being used in my friends SCCA car today and they are over 15 years old!
My new 190e race car is getting Bilstien Sport Front and SPAX Adjustables in the rear. I chose the SPAX because they are easy to adjust at the track and it came highly recommended by an AMG engineer.

Bilstien Front and Koni rear is also a good combo.