After a couple of hours in WW1 these are my personal observations. The D7 seems the easiest, most forgiving plane to fly. It has a good control response on all axes. Especially the roll rate puts it above the Dr1. The stall is very predictable and it never departed on my while manouvering. The dive capabilities are much better than in the Dr1 where you start losing parts with no or very little warning. The high views generally are better in the D7 than in the Dr1.
While the Dr1 might outturn you flat you can always go vertical or oblique to keep pace with it - and the 3 wings make for a big target to shoot at. I only know the Camel as an enemie and always felt I could keep it at bay with both the D7 and the Dr1. The biggest pitfall of the Dr1 for me is the dreaded flat spin. I lost more planes while sliding down sideways than to enemy fire. I can make some nifty aerobatic manouver when done right but chances are I cannot recover in time...
All in all the D7 seems to be the better rounded dogfighter. Not beeing the best in any category but combining all the need treats of a fighter airplane.
ATM I spend most of the time in the Dr1 just not to be in the D7 crowd...
and I always loved the Red Baron.