Whichever you choose, Hong Kong University is better. Although the University of Hong Kong is not as good as some engineering schools or science schools in foreign countries or Chinese mainland, it is such a leader in Hong Kong. After all, HKU is also the top 4 university in Asia, a world-renowned institution with guaranteed scientific research strength and education level. And it's worth experiencing the learning atmosphere of a famous school.
Hong Kong Polytechnic University can do the same. If you want to find a job, a university of science and technology is enough. Applied, that is to say, you come here to teach you some practical knowledge, and you can work in an engineering company in Hong Kong after graduation. Employers in Hong Kong also welcome students who have graduated from science and engineering. It's hard to say in the mainland.