Questions like this are usually not allowed but since the price of a brass nozzle in Switzerland is 15.90 and the average price of a nozzle from Alibaba or AliExpress is less than 0.10, and nozzles are something you exchange frequently the issue becomes of such magnitude that we need to have a simple answer to the very straightforward question:
Do nozzles from China offer the same quality and results?
I use cheap brass nozzles through the "A" place and they are almost certainly Chinese.
When installing a new nozzle I use a drill bit in a pin vise in the large counter-drilled hole on the top side, pressing pretty hard to assure there are no drill chips in there, either loose or still attached. I follow that with a nozzle cleaning pin of the appropriate size, then a good blast of Dust-Off or the equivalent from the "W" place.
I get reasonable nozzle life and performance.
In my case nozzle replacement is nearly always from blockage, almost never from wear so I've never considered it worthwhile to use premium nozzles with better wear resistance.
Up until this year, I used the cheap nozzles - the original that came with my Ender 3, and both the ones that were supposedly by Creality and appeared identical to it, and similarly cheap ones off Amazon. I never had any problem with them that I attributed to nozzle quality, but I went through them fairly quickly since they were so cheap, just swapping one out if it got a lot of buildup that was hard to clean off rather than bothering to clean it well. I would say they are perfectly usable.
However, if you're already used to paying more for a nozzle, I would strongly recommend ditching plain nozzles and going with the Bondtech CHT. The performance and quality improvement from it is drastic. It gives more improvement to flow than going from a standard size block to a volcano size block (see Stefan's tests on CNC Kitchen), and a lot less backpressure, so you can get by with lower values for Pressure Advance/Linear Advance, which put less stress on the extruder and get more consistent extrusion. In terms of ratio of printing performance boost to price (not to mention ease of installation), it's probably the single best upgrade you can make to a printer. And while it's not a special durable material, it is coated, which makes it a little bit better than plain brass.
