I can only speak for KUST.
I believe out of the three you listed it is the cheapest by a few hundred RMB.
Admin is quite slow and can get frustrating as with the other two so I have been told.
Classes are quite small, between about 4 to 10 students per class. Teaching style can be boring (depending on your teacher) with no activities or language games really, again, as with the other two you mentioned.
Text books are decent. Though, if like me, your speaking/listening is good but your reading/writing suck, so decide to take only the speaking/listening class to improve on that, you'll be surprised to know that even though you took the speaking/listening class you will still be expected to read and write Chinese AND there will be reading/writing in the final speaking/listening exams. Go figure...
Will you be living in the dorms? If so, expect trouble with the water - it's solar powered so if you get a rainy day/week, no hot shower for you. Also, you need to pay for a full year rent up front, even if you only study for one semester. You get whatever you are owed back the day you move out.
Wi-fi is decent.
Gates close at midnight, so if you like night-life, expect to either climb the gate or pay for a hotel. Living out of the dorms obviously eliminates all of these problems. However, if you really want to practice Chinese then the dorms would be good as your roomies will probably be from SE Asia, so you will be forced to speak Chinese.
Canteen food is average and super cheap.
Location of the campus for language students is right in the centre of town, so very convenient.
Hope this helps!