Whenever push the pedal to the floor, the passing gear does not engage as it should. You would think it would shift into the lowest gear it could to get the most acceleration. If I'm in OD for example, it feels like it is shifting into 3rd, then 2nd, and back to 3rd all within a couple seconds, when 2nd would be the gear of choice until it hits the red line. The car is almost gear hunting any time it has to shift down under moderate to heavy throttle. It's the 4L60-E and just recently had the fluid totally flushed and the filter replaced. I have a video so people can hear what I mean. The engine sound tells it all. In the video, my foot is on the floor until the very end. All that RPM changing is the issue at hand.

http://www.youtube.com/watch?v=WiGxju9hOPY