I have been at MTC for one quarter now and about to go on my second. I have spoken to several people who have been there for a couple terms as well as students in other classes. Learning a lot and getting your money's worth at MTC mostly comes down to the teacher you and the classmates. Everything else is on your own time, how much you study, and/or the extra effort you put into improving your Chinese skills.
Classmates:
Most of the students in the reading/writing classes have told me some of the same things regarding what their teachers have told them. Many of the teachers at Shida prefer to teach foreigners who have little or no speaking background at all, meaning those in the audio textbook classes. They are less inclined to teach the reading/writing classes because they are filled with a lot of ABC's, and/or "hua qiao 華僑 " (overseas Chinese). If you don't know what an ABC is, it stands for American Born Chinese. Overseas Chinese are people with a Chinese background, but raised in a non Chinese speaking country. The reason man teachers prefer not to teach this class is because some of those students were forced to come learn Chinese from their parents. Some are either jobless back in their home country, and came to Taiwan to learn Chinese because they had nothing to do, some haven't figured out what they want to do. Overall, if they are not here because they want to be, they lack the motivation to work hard and pay attention.
When I heard this I asked my teacher about it and she even admitted this was true, that if students aren't willing to learn, they can't really teach. However, my teacher lucked out, because she has gotten 3 quarters of hard working students who have a strong interest to learn. She also teaches another class for the non speakers in the audio books and says indeed she has never had difficulty teaching them.
One friend in another class, is very passionate about furthering her Chinese education, but the rest of her classmates slack off and sometimes don't even show up to class, or are even late. They even text/SMS on their phones right in front of the teacher. Her teacher is very relaxed and doesn't know how to handle it, thus she doesn't teach very much and teaches at a slower pace. All of my classmates are so motivated to learn that our teacher sometimes gets overwhelmed.
Teachers:
Another friend in a reading/writing class has said her classmates are all okay, but her teacher doesn't teach as much and only sticks to the book and doesn't teach any new vocab outside of it. My teacher on the other hand, teaches a lot of vocab that is not covered in the book, but that she feels is of practical use to us. She would take parts of word, like the radicals, and put them with other parts to create a new word for us.
Also, every teacher has a different method and style for teaching. My teacher gives daily listening/writing quizzes and makes her own chapter tests and handouts. My friend's teacher doesn't do this and also uses their workbook as their chapter test. As you can see, there is no set curriculum for what the teacher needs to do other than cover what is in the book. How he/she decides to go about teaching the students, and how much he/she wants to invest in them varies. Every class moves at a different pace, while supposedly you are supposed to cover a lesson per week.
Also, one girl has mentioned to me she tried switching into 3 different classes before finally settling on one. One of the reasons was her class was full of people who didn't care much to learn, due to the fact that they had a very easy/relaxed teacher the term before. Another reason, was that she didn't like the teacher's style.
Now for the audio classes, the challenge in getting a bad teacher here is that some of the teachers don't know English very well. 2 friends of mine are in the same class together, one of English background, the other of French. Both of them say, when they're class doesn't understand the meaning of something, their teacher is unable to translate it to them. Sometimes the teacher can't even understand their question or what they are trying to ask. It should be a requirement that all MTC teachers have a certain level of English proficiency. Especially, those teaching foreigners with basic Chinese speaking.