I am not the Uber k4 Stick by any stretch of the imagination but I have learned it is an awesome plane. Most of my k4 kills come from crossing shots at about d200 - d400. One move I have had a decent amount of success with is against a plane with an alt and speed advantage.
Bad guy at high six. He begins to make his run on me, I cut to about half throttle and start a lazy right hand turn. As he gets closer, licking his chops at the easy k4 kill he is about to get I roll and start a low yo-yo. The bad guy knows the k4 cannot turn with him so he cuts his throttle to start the turn fight. At the start of the break I am almost blacked out pulling up into the verticle, I see the bad guy wants to start a rolling scissors. I am coming up to him at full power, he crosses my 3-9 line and I am rolling with him (it is important you roll, and do not try to turn). There he passes, I am continuing my roll, soon he will cross in front of my nose at about 250 yrds, right where I want him. The snap shot ability of the K4 is awesome. As we continue the start of this rolling scissor, he passes right in front of my nose, I pull the trigger at about a plane to 1/2 a plane length in front of him. One of two things happen, he loses a wing or he goes straight to the tower.
I have used this maneuver on some of the better sticks and it worked out great. It does take some practice and a lot of throttle control. When you have it right it is a lethal combination.
WMTom