Initially, I didn't like it, but the dealer only had a spoiler-equipped car in the color combination I wanted--SGM with gray interior. Now the look has grown on me, and I appreciate being in the minority as most cars I see on the road don't have it. It seems that the batch of cars that happened to come in when I was car shopping all had these, as a nearby neighbor's ES also has the spoiler, and he bought his just before I did.
The lip adds a little kick to the rear end, so the car looks a bit more youthful. And yes, I'm on the junior side of the ES-buyer spectrum.