They are all big companies and central enterprises. What kind of products do you want to buy? Life insurance companies have certain guarantees because of the establishment requirements of other companies. PICC is one of the four central insurance companies in China, and property insurance is its main business. Life insurance is said to be more affordable. However, it depends on the terms and conditions. When the company has strength, it is even more important than the product. Products mainly depend on terms, insurance liabilities, exclusions and so on. Finally, it depends on whether the agent is professional and dedicated. This is very critical.
Further reading: How to buy insurance, which is good, and teach you how to avoid these "pits" of insurance.