Third sister and Xinmin have to take the entrance exam, and they can only enter if they pass the exam. I think Xinmin is actually good ~ both teachers teach in No.2 Middle School.
Sanmei is the best. No.3 Middle School has good facilities, good teachers and good classmates. You will find it slowly in the future. Generally, you can study hard in Sanmei, and you can continue to go to a prestigious school in high school.
Xinmin has accommodation, but the conditions are not very good. The accommodation in the middle school attached to Xida University is not as good as that of Sanmei. However, people who come out of the middle school attached to West University seem to be very good at English and Chinese. Those people in our class from Xida University are very talented ~
I haven't heard of it for 37 years ~ it's adapted by the school again ...
In short, if the family is not short of money, go to Third Sister.