How are you going to feel if 25 people tell you the aftermarket radiators are junk?? You already did it...
I'm not going to tell you that but I also replaced my '89 300E radiator about a year ago and purchased a rebuilt MB radiator from a place in Alabama. "Jim's Radiator" I think. A free plug for Jim. He sells new aftermarket and also rebuilt originals. There is not much difference in price so it basically came down to which was better. He felt that the rebuilt unit was better than new aftermarket. The warranty was the same also so I took his advice and did the rebuilt. It has only been a year but it looked brand new when received and works great!!!