By way of preface, this is all opinion. As far as I know, there are no empirical studies on this.
I suspect that a US or EP examiner is much more likely to reject an application for lacking novelty or being obvious (compared to China, or for that matter, Japan, the UK, Australia, Canada etc). If your yardstick for rigor is the likelihood of rejection, then certainly those other jurisdictions are less rigorous.
However, I would question whether that is an appropriate definition for rigor. Certainly a US examiner combining 4 unrelated documents to justify a non-obviousness rejection or an EP examiner declaring that all the novel features of a claim are mere implementation details with no technical effect based on the common general knowledge does not necessarily seem rigorous to me. Instead, in my view, it demotes the patent application process in the US and EP to a crapshoot, where you can do no more than hope the examiner is in a good mood on the day.
That said, what you describe of Chinese examination seems generally representative of my experience. The Chinese examiner will generally adopt the IPRP (or the US or EP analysis, if they are available), and expect the applicant to address the rejections there. However, I should note that that is common among most offices (other the US and EP). And in fact, national offices adopting the analysis from the international phase is precisely one of the intentions of the PCT system. The fact that the US and EP choose to repeat the search and examination anew in most cases does not make them more rigorous necessarily (and I would cynically suggest they just want more search fees for themselves).
Are Chinese patents worth much?
It depends if you think a patent for one of the world's largest economies and the world's largest consumer market has any value. A Chinese patent would certainly be my third choice of jurisdiction (after the US and EP).
In fact, from the point of view of an applicant (and ignoring broader externalities), weak examination is great. An invalid granted patent has significantly more value than a refused application.