The fundamental problem with counterfeits is that they aren't held to any published spec, so comparing your experience to mine isn't really meaningful...other than being not genuine, you can't generalize anything about counterfeits.
It was so long ago, I had to dig up notes.
On the performance side, the counterfeits I received couldn't be clocked anywhere near the 10 MHz limit specified by a genuine MAX7219; one package pin that should be tied to GND was floating internally (contributing to poor thermal performance); but the real showstopper was that intensity control didn't work for shit.
My records reflect nigelectronics on eBay as the counterfeit seller. This is the address I was instructed to return the counterfeits to when I called them out on it for a refund (I eventually got the refund, but threw these counterfeits in the trash where they belong):
Cheng Kwok Hang
15F, BLK 1, Aldrich Garden, 2 Oi Lai Street, Shau Kei Wan, Hong Kong
On the business side, I effectively wasted 10 days lead time in a tight pipeline just waiting for this garbage to arrive + more time/frustration isolating why the chips were failing initial tests; swallowed ~$700 out of pocket + expedited shipping for a single BOM line item to purchase genuine replacements from an authorized distributor; and looked like a complete hobbyist amateur to a collaborator in NYC (who was working on the mechanical side) as I had to explain why my stupid decisions meant he'll have to wait another 2 weeks before receiving the pre-production prototypes I had promised (which meant his clients ultimately had to bear that burden). Then there was all the manual rework which I didn't even keep track of.
This was my first semi-pro side gig out of college, and juggling all the unexpected curve balls with a fulltime day job was quite stressful.