This is a wonderful strip overall. Although the punchline (or punch panel) is kind of flat and could have been done in a daily strip, the buildup to it is marvelous. Charlie Brown and Lucy's argument is wonderful and energetic, especially panels six and seven, where the characters lean into the other as they express their anger. Although most of the strip is just talking, it's far from static talking heads, Charlie Brown really acts out his frustrations.
The first two panels make the strip, for that feeling of dread Charlie Brown suffers through knowing what's about to happen while powerless to stop it. (It also gives us another use of thought balloons, which are far from a standard part of Peanuts at this point.) Lucy, as is often the case, argues from a misguided position, but she still believes in it and defends it.
I'm not sure I've seen a strip yet with this much shouting and anger. That recent Lucy and Schroeder strip had Schroeder quite angry, but it was a single burst of emotion, not a sustained assault. This seems like a breakthrough strip to me, in terms of Schulz's depiction of conversation and anger, and just the energy he infuses into it.