Glad to hear you are considering Midd!
I am a first year student about to wrap up my second semester here. I can only speak for my personal, albeit brief, experience with grading here.
Grades here are not curved (to my knowledge), and they are done on a standard 4.0 scale. In general, for classes in the humanities you receive few grades (papers and exams) while classes in the “hard” sciences have more explicitly grades assignments (problem sheets, lap reports, projects etc.)
For example, one of classes in American Studies right now breaks down like this:
20% active class participation
15% paper 1
20% paper 2
25% paper 3
20% two reviews
Some classes are much more exam based. The sociology class I took last semester was graded solely on one paper, a midterm, and the final. On the other hand, some classes work more like high school grading in that regular assignments are graded more frequently. My Chinese class has weekly homework, weekly quizzes, tests every three weeks, and exams (all graded and contributing to your final grade). It really just depends on the type of class.
Small classes absolutely means you should make an effort to actively engage. Professors or classmates will without a doubt notice you aren’t there or don’t participate. How heavily this will impact your grade depends on the grading breakdown and individual professor.
After two semesters here, I have a 3.93 GPA (will likely go up after spring grades are finalized). I work hard, like school, and had a 3.97 high school GPA, so my experience may or may not reflect the average. I don’t talk GPA with friends or classmates much (it just doesn’t seem to come up at least in my experience), so I really can’t say. But achieving at least a 3.7 is doable if you put the work in.
I should mention some classes are notorious GPA killers (beginning Chinese and some sciences). With these classes, if you’re really GPA focused it helps to have some background experience.
Finally, it’s not really my place to tell you how to look at school, but I can’t help but throw my two cents in about grades… I honestly don’t think GPA is the most valuable way of looking at college academics. Results only matter to a certain degree. You would be coming here to take advantage of the great programs, staff, and resources not to hit a certain number. Reaching 3.7 won’t necessarily mean you are doing better in the long run if you are only trying for numbers. Experience and knowledge when you walk out of here in four years is really the kicker. I don’t know your personal situation, so of course take my view with a grain of salt. Something to keep in mind still.
Basically, you get out of it what you put in