Gollevainen,
You can do badly on a standardized exam, like the SAT, and still get into a prestigious school (Harvard, Stanford, Yale). A very big factor for admittance here is do you have any family in the alumni in the school in question? How important are these alumni members, ie. how much money do they donate?
Prestige schools tend to be extremely hard to get into regardless of your test scores (Last I checked, Yale has an acceptance rate of 5%). Connections are key.
But prestige schools are different from technical schools. It is much harder for a moron from a wealthy background to get into a technical school, such as MIT, where test scores take priority. Another category of American colleges are state schools, which give a higher priority to grades than to college entrance exams. Because state schools get state funding, so they are much cheaper than prestige schools or tech schools, and most American college grads are from state schools.
American colleges are expensive and most students (even state school students) graduate with significant student loans to repay.
Ideally, if you want to go to an american college, you'd apply for as many scholarships as possible, and look for a state school that has highly esteemed science and engineering departments. It is not unheard of for a state school to have engineering departments that rival technical schools, and of course there are technical schools that are very prestigious.
Of course, none of this matters until you compare the graduate schools. Undergrad isn't so different from college to college with the exception that technical schools tend to have cooler (more expensive) laboratory equipment for their science/engineer students to play with. On the other hand, technical schools tend to have crappy teachers who care more about publishing their own research than if their students learn anything.
It is in the graduate program where technical schools really shine, as these are primarily research institutes anyway. Providing diplomas is their secondary function.
