Just throwing in an observation:
We were flying on our server last Sunday in a mixed group of Central aircraft: Albatros DVa, Fokker Dr1 and Fokker DVII. The flight leader was flying a Fokker Dr1. We were at 3400m. At the same time we hit the autoleveler. Results: The Fokker DVII flew alongside the Dr1, but did not overtake! The Albatros DVa couldn't keep up at all.
Talk about an immersion killer!
That is indeed quite disturbing, both the D.VII & D.Va should have a comfortable lead in speed over the Fokker Dr.1 at 3,000 m, as-well as at SL.
Based on the data available I believe that the top speed of the Fokker Dr.1 was around 180-185 km/h at SL, and around 160-165 km/h at 3,000 m. The std. Fokker D.VII and Albatros D.Va should be aleast 10-15 km/h faster.