JAYB, I got the impression that the original question from jingzy was more related to dimensional differences between manufacturers and compatability of primers to cases, not the quality of the primer.
I have obviously caused confusion by relating to why I don't personally purchase CCI primers, which is more due to the attitude of the suppliers than the present quality of the product.
Having used Federal (my favourite), RWS, Sellier & Bellot, Remington, Winchester and one or two others over the years I still find the comment that there are microscopic dimensional differences between manufacturers to be correct. These dimensional differences can occasionally lead to reluctance to seat or a sloppy fit in some cases, either could be unsafe and should be avoided. Like yourself I look for acceptable accuracy and reliability not for bench rest standards.