Of course, if you have a smaller class size, then teachers will be able to allocate more time to you. That's obvious. If you're at university, one lecturer will not be able to tell one student from another (if you know what I mean), he/she wont be able to know if you're away from a lecture, if you haven't done your "homework" or anything else.
If you have a smaller class, then the teacher will be able to keep track of all his/her students, where they're at, be able to talk to you more often, and so on.
That's not to say that in a "large" class, you won't be able to have your say. If that's the type of person you are, you will always speak up and move away from the pack/herd. Even in a class of 20-30 students, if you've got something to say, I don't think anybody would "hold back" just because they are afraid of the other members in the class, that's not the case here at my school. Everybody gets to speak their mind and everyone listens, of course, if it's funny, then the speaker gets a laugh.
We don't put anybody down for "not understanding" though.
Just my 2 cents, don't run me over.
/edit
If you're in the country, or if you're in the city, it will still depend on the student and his/her academic ability. If you had a student growing up in the city, and he/she is academically capable of performing well in a given subject (say IPT), then he/she is competing against city students as well, in the same subject.
Teachers are another issue, as well as which school the student attends. It is all about circumstances.