How to choose an eSIM for China + Hong Kong?

For a trip to China and Hong Kong, I'm planning to purchase an eSIM so I can use mobile data with my device. During my research, I've found a pretty large variation in prices for my options (as much as US$10 – US$15 difference between least and most expensive) controlling for variables like validity length and total data cap. For those who use eSIMs frequently, my questions are:

• What are some of the things I should look for when comparing plans?
• What might I be trading off when going for a cheaper plan (assuming validity length and total data cap is the same)?

I'm also open to recommendations for eSIM merchants or network providers for my destination (China + Hong Kong), provided there's good justification.

I used to use an eSIM from China Unicom (cUniq I think), which I used from my travels around Asia. I don't need it anymore, so I'm not up to date, and since I live in HK, I have a post-paid SIM card with roaming privileges.

However what you should look into is speed (what max speed, and whether there's a speed downgrade after a certain cap); coverage (which network do they use in HK and China?); how to top up.

If you're coming to HK first, I'd just buy a prepaid Bay Area SIM from one of the top 2 networks in China, China Mobile or China Unicom. It'll give ypu coverage in HK, Macau and the Mainland. And allow you to use Google etc in the Mainland.