CityU or HKU

I'm a bachelor's student majoring in Asian Studies, currently studying Mandarin + the economy and politics of China. My uni is partners with both City University of Hong Kong and Hong Kong University.

I'd love to travel around the region and explore HK as a city so I'd like a uni that teaches decently but preparation/homework-wise is not too harsh (my current uni is №1 in the region and it is VERY academically challenging, I'd love a decent sleep schedule for at least a semester, and fun learning experience).

Which university would you recommend for an exchange semester? What teaching methods are used? What kinds of assignments do you have? How challenging are the exams? If you could share your academic life, it'd be very helpful!