The major complaint is always that we spend more per student than any other country, but that our test scores are lower than that of other industrialized countries. But it's hardly a level playing field. Most major countries now have universal education, but in other countries it means something different than it does here. Originaly, universal education meant access; Anyone who wanted an education could get one, according to his or her abilities. This continues to be what universal education means for the rest of the world, but the US has shifted from providing the opportunity to recieve an education to educating everyone. I personally think this is a great thing, but it has some consequences. Traditionaly, "bad" students would go through primary education, but would then leave to work on a farm or find a trade. This continues in the rest of the world, but in the US we've found that you can educate the "bad" students, it's just expensive. And you're not going to be successfull all the time, so a chunk of those "bad" students are going to drop out.
So yeah, we spend more money per student, and our gradutation rate is lower (BTW, graduation rates are based on the number of students who enter secondary school, NOT total population, so the lower the percentage of your population that starts high school is, the better your gradutation rate is going to be). But nobody ever mentions that it's bound to cost more and have a lower rate of success when you include everyone rather than sending the "bad" students on their way after grade school. These studies are like a car magazine saying Chevy cars are faster than Ford cars, but failing to mention that Ford had to race every car they make, and Chevy only had to include the Corvette and Camaro.
Now, I must admit that this situation is changing...more and more other nations are moving towards true universal education. For instance, until pretty recently, a lot of countries would remove students from secondary school who didn't test at a certain percentile. Most places aren't that cut and dry about it anymore, but as things stand right now, no other nation has such a focus on EVERY citizen attending secondary school.