Well here is the game I just played: I was black and had 3 stones handicap against an 8k, but it was hard to keep up with white.
I don't really have experience with any kind of handicap.
I used my 25 minutes as good as I could and won by 5.5 points, but I made some mistakes and I think here and there are still some useless moves or at least slow moves.
At some points I was not to sure what move is better. I also first thought my group on the left side is dead but later in the game I managed to save it.
Anyways as always I would like to hear some comments so that I can improve my game a bit.