I've used MAX7219s from Tayda and while their appearance fits that of the fakes, they seem to work fine for me.
But recently I bought one of those 8-digit LED display modules on eBay, it had an SOIC MAX7219 on the back of the board. The thing worked, but drew about 300mA. The MAX7219 ran very hot to the touch. The LEDs themselves were OK, I removed them and it hardly changed the current usage. I breadboarded a similar circuit (with the Tayda part) and it uses less than one-tenth of the current.
Don't know if it was the MAX7219 itself or something else wrong with the board, but I demanded my money back. At first the guy wanted to give me a partial refund, saying "as our item is very low price ,it may be not as good as other ones that is more espensive for this case ,can we partial refund to ease you ?"
Of course his web page said nothing about the product being "not as good" so I got pretty direct with him and he did give me a full refund.
Once every few years I have to buy something on eBay just to remind myself why I shouldn't.