Belowis a slightly better than average group for me at 40 yards, followed by a 70 yard group shot by my buddy Dan and I screwing around at the club.
Most groupsat 40 yards I will end up with 3 touching the black dot, bad groups on average will have 2 in the dot. My flyers these days aren't so bad though, the black dot here is about 1.5" in diameter and most times I miss the dot I am less than a 1/2" off it, I am able to keep the worst groups with flyers still under 4-5" at 40 yards as well.
In regards to the question about how we do on a brown/black target with no dot marking the spot......a good shooter with 3D experience would surprise you.Honestly a good shooter is a good shooter and this isn't going to affect them much. I know myself personally at the local 3D shoots from open stakes with shots averaging 33-40 yards and some extending out to 50 yards..............I am averaging 10-12 X's on a 30 target course with a pin sight. From the hunter class stakes last year (35 yards and closer) I was averaging 13-17X's.