I'm signing in only because the reviews posted seem to be three years old and an update is apparently really needed.
I'm a parent of a current 6th-grade student at CSS and we're very, very happy. The teachers in our child's classes are engaged, very excited about the curriculum, and great with the kids. The administration appears to have a good working relationship with the teachers and cares deeply about the kids and the school. The dress code is not draconian but works. Our kid's experience socially has been great-- the teachers maintain an open, friendly environment, and vibe among his peers is supportive of each other and the school. The intent to have qualified kids in upper grades take classes at Columbia University appears to be working, and we're looking forward to that in the future.
So why not the coveted "Excellent" rating? A couple of pet peeves, and a few outside pressures. Our child was literally weighed down with a lot of homework this year-- hours at the desk as well as pounds and pounds in the backpack. The after-school programs are less coherent than they were at elementary school, which might be the simple result of being in middle school but still requires some scrambling. More importantly, the school expands into 12th grade in 2013-14, and it is bursting at the seams in its shared building. Since the school size is growing every year, it makes more acute the ludicrous budget pressures the DOE places on the school. Again, perhaps this is normal for an NYC public school, but it's still shocking.
But ultimately, there's this: if we went back in time and could choose our middle school again, we'd choose CSS in a heartbeat.