Throttle/pedal link 2004 Tahoe

My new 2004 Tahoe acts very strange when accelerating and before I argue with the dealer, I would like some input if anyone has any. The throttle is very, very unresponsive to the gas pedal. Sometimes, (not always), I hit the gas and nothin' for about 3 seconds (that's a long time in heavy traffic). My cruise control acts stupid, downshifting at every hill on the highway. The throttle will GENERALLY do what I want, but it acts like it takes the gas pedal's suggestion and then decides to act in it's own good time. Someone told me there is no cable anymore (electronics instead??). Is this the normal operation that I must live with, or should I see my dealer?