Yes, "Over the Hedge" had heart. The characters are very appealing, and when Hammy says "I'm not stupid", it breaks my heart. But its biggest strength is in its humor. The van exploding when a wagon of food lands on it. Dwayne shooting at anything that resembles an animal ("BUNNIES!!!"). The whole sequence at the end with Hammy. The movie, asWith OTH the emphasis of the reviews is the "humor". With Cars it's the "heart." You decide which is more positive.
With "Cars", there was humor, and plenty of it, but clearly what they were aiming for was heart. There were a lot of those "Quieter" moments. I can't even remember them all since I've only seen the movie once.
So, what I'm saying is, critics may notice the heart in "Cars" more because its the film's strongest aspect. Likewise, they may talking about the humor in "Hedge" more for the same reason.