Dilworth's stuff is great, but "You're not perfect" worked so well because the show was almost always in 2D, rarely breaking into another animation medium except for dramatic effect. Courage's animation was never as good as that in a Spümcø cartoon, but the showrunners knew how to contrast solid 2D scenes with computer-generated storyboards and freaky, rather inspired premises/character designs. So Eustace's Trumpet just comes out of nowhere and, on top of being perfectly imperfect—like if Victor Mature was an alien from space invading Courage's dreamtime—nobody expects this kind of creature to pop up on screen. It's the best kind of jump scare, since it actually lasts with you or is so effectively horrifying you have no choice but to repress the experience (like I did up until recently).
This 3D stuff looks too smooth and full of "real world" dimension, and the cloud creature isn't that compelling a monster, not like even the UFO chicken. It feels like a compromise made to save money and satisfy the target demographic's self-fulfilling, complacent familiarity with CG animation (one reason why I like what MLP's doing with stylized 2D, boring as it is).