@Janjal, some other consideration.
One aspect of learning, is your fellow students. If most of the students in the class are Asian, they fit in well with the learning style, and you will be the odd one out. If you do a class with mostly Japanese SS they will have no problems with reading and writing and you may get your confidence undermined. By contrast, if most of your fellow SS are western, then although the norm in a university is the Chinese teaching style, you will all be in it together.
A few universities (e.g. Shanghai, Jioatong) separate the students and have a different class methodology for western SS, than they do for SS of other Asian countries.
If your teacher is a fresh graduate of teaching Chinese to foreigners course, they may be a bit rigid in their methodology. A more experienced teacher will know more of the quirks of teaching westerners.
One advantage of learning in a university is the cost is much lower, and there may be cheap accommodation. Also if you are a younger person, it is easier to connect with local students who may even be your dorm mates.
The advantage of learning in a private language school is smaller class size, more flexible teachers, and different methodology and course materials.
The other big difference is course materials. Most university courses have a lot of university vocabulary (admissions, cafeteria, library speak) that you will not use, and this is front loaded on the course and can be frustrating if you want to go out and use the language.
Cheap places to live. Kunming is not cheap, most Chinese tier 1-2 cities are not. As @waynecaoaus noted, most of Zhejiang uses Mandarin (maybe because it is not mother tongue but learned, it is more standard) there will be lots of small cities along the coast dependent on trade that use the language daily for business. These would be cheaper places to live.
As for the other things, maybe it comes down to whether or not your focus is learning the language, or if you are using learning Chinese as a shoe in for visiting China longer term. A lot of students are probably the latter.