I find a little bit funny that people judge a car's performance by a specific race result or result's... As most people know top drivers can win races with pretty much any leading buggy..
The RB buggy actually is Euros B champion, so the car must be fine!
Anyway if judging from European results point of view, the D812 is not a top car, and apart from Tessman who get's top results at top events???
My advice is get the car who's support and parts is best..