I have had both. And there was no detectable difference. I currently have the chinese one.
Actually my chinese one is one of these, which is likely also more than you need. Its almost exactly the same as the 15, but a few more bells and whistles.
https://www.ebay.com/itm/FLUKE-17B-Digi ... SwEK9T13qIThey are basically the same thing, but the 17 also does temperature (not needed by me), and frequency, and so also duty cycle etc. But unless you have a use for those things then they are otherwise the same. I do which is why I ordered the chinese one to replace the 15. Quality wise, identical. Different language writing on the label is about the only difference.
I also have a fluke 289 which is a lot more than anyone needs...
Bought much later. Its big and heavy, slower to use, but does everything and then some. So its
very useful for some technical jobs only if you know why you need it. I do a lot of hobby RC stuff.