Kristen
I can't say about other academic programs but the Animal Science department is incredibly close-knit. Everyone knows the professors and the other students in the program. My favorite classes were taught by Dr.Howe because he is really funny but really cares about his students. Everything he taught has been used again in other classes and in post-grad life.
Erin
Some classes are big, but the more specific they get, the smaller the class and closer relationships between students and teachers. Students are very competitive.
Alex
There's a stigma with UMass because it's a state school, but you'll learn the same information you'd learn at Harvard and the professors are just as talented and smart as the professors at those ivy league schools. Isenberg is a top business school. UMass does TONS of scientific research that gets published in the top journals. Commonwealth College (although I personally thought it was a HUGE waste of time) apparently has a great reputation across the US, being compared to UC Berkeley and other amazing schools.
Allison
Strong academics. Good business school.
Gene
The degree to which you get to know professors and students is largely based on what you're studying. In majors such as Communication (my own), there are a lot of classes with a few hundred students in them, making it very hard to get to know people on a personal level. However, it isn't impossible, especially with small discussion groups and professors always available for office hours and extra help. Majors with smaller numbers, like music, are much easier to get to know professors and students in. I took at least one music class for each of my last six semesters at UMass and got to know the music students and faculty much better than I did the Communication faculty.
Andy
I can't talk for any other departments, aside from the two I picked for my major: physics and computer science. Coming to UMass, I had no idea how great academics in these fields actually are at the school. The computer science program is actually undergoing some fundamental changes right now, which I think are for the better. You have the ability to pick a particular track (think subfield), and focus on it. So, if you're into AI, for example, you can focus on that a lot earlier.
The professors in both majors were always available and tried their best to accommodate the students needs. Aside from office hours, the greatest part is the research opportunities. I worked on various research projects starting sophomore year and continued until graduation. All of them started with me looking at what kind of work was being done and asking if I could participate in any projects. This is the best way to get to know the professors and, if you're thinking of grad school, get those important letters. A letter starting with "s/he did research for me" cannot even be compared to "s/he did well in my class." Also, if you're looking for a summer job, ask professors. Often you can stick around the area and do meaningful research and get paid for it (~10$/hour)!
The classes in the majors were small (< 30, with some being as small as 6-10 students). Of course, for other majors this may not be the case (psych, for instance). The physics department is pretty small here, so scheduling conflicts were frequent, since they'd only offer the class at one particular time once a year. Usually, you can work around those and make sure to think about what you want to take ahead of time.
Finally, you can take honors classes or honors colloquia here. I would highly recommend them, since you get more "personal" attention and usually they cover some interesting topics, aside from the usual. The most fun one for me was a course in architecture, where for honors we wrote a game for 8088 assembly. As for the value of commonwealth college, it's a pain: you have to take 3 semesters of dean's book - read a book and talk about it and write 2 essays, an honors I - think literature, and some honors course in major, and finish with an honors project/thesis. The biggest complaint is dean's book, but it meets only once a week for 2 hours for only a half of semester. I'd recommend doing comcol just because it forces you to do a project/thesis. Of course, you can do that without it, by working with professors.
Dan
The smaller departments tend to have great professors. Take time to do a research project or talk to them at office hours, even if its a big class. When you get to higher levels, make sure you participate and put yourself out there so that people know your name. Doing an honors thesis is a great way to meet a professor and get chummy with faculty.
Meagan
Since I'm a Comm major, there are like 500 people in my classes. Its a popular major. I've heard that other majors are smaller and more intimately staged classes are held. I don't think I'll experience that while I'm here but I'd like to. Sometimes it sucks that the prof doesn't know anything about you and you have to rely on a TA on a powertrip for your grade. One of my best friends was my TA last semester, it was a weird experience for me. I think the profs are willing to get to know their students if the students are willing to make that happen. There are some students who are annoying and sit in the front and suck up and ask all the questions. And then there are students who don't show up until exam days. Its kind of like a big high school class...a little something or role for everyone to fit into.
Jamie
Teachers do not know most of their students. Classes are too big even the SPorts Management ones. Umass education is geared towards getting you out with a diploma. No one cares if you learned or not. Dept advisor wasn't any help and neither were the teachers. Everyone is out for themself even the staff
Alex
All students are different when it comes to studying, but your style will most likely fit in just fine. The student tutoring in the library is great service, and has helped me big time when it comes to harder subjects for me or reviewing essays.
Professors will know you when you make yourself known. In a large class, it is up to you to make yourself known, if that is what you want. Most of the time, large classes will have a midterm, a final, maybe a paper or two, and thats it for grading. If you can show your teacher that you have what it takes to get good grade through tests, you should be fine. If you are struggling, you need to make yourself known and show that you care. All the professors I have had in large classes are glad to get to know me. Professors in smaller classes obviously will learn your name because grading is usually much more based on discussion and participation.