As the name of the program says, Intensive classes are going to be intensive.
From what I have seen from my friends attending the Ewha and Yonsei language centers (while I was an exchange student in Ewha) is that it depends on a couple of things:
Number one is very important: if you are Japanese (or fluent in Japanese), learning Korean will be extremely easy for you and you will have lots of free time to play around.
But I guess there are not many Japanese speaking people around this forum.
Anyway, number 2 is that when you enter the program with pre-existing knowledge, it might be harder for you rather than someone who does not know anything.
Concretely, if you have 0 knowledge, you will follow the program from the beginning and you will always meet the requirements (since there are none
But if you have pre-existing knowledge, it is very likely that the different levels will not fit with you perfectly.
If you have high knowledge of grammar but low on vocab (which, in my opinion, is what is going to happen if you follow KoreanClass101.com exclusively), you will either be put in a high level where you will have to study much vocabulary every day (could be as high as 60 or 100). Or you might take it easy and learn the vocabulary progressively with a lower level class.
But when it comes to teaching methods, I can only speak for Yonsei and Ewha.
Ewha seemed to have much emphasis put on talking and personal work. Whereas Yonsei put more emphasis on grammar and structure.
My opinion is that if you are looking for a short-term learning experience: go for Ewha.
If you want to be more proficient but ready to stay longer (1 year, 1 year and a half), go for Yonsei.
These 2 campuses are near Sinchon, with an advantage for Ewha which has numerous restaurants, girl shops and a subway station near its main gate.