Hard to say without having one in hand to study. Some of the sellers seem to have good recent feedback from multiple buyers for various flavors of LSI cards, so it is likely to at least work out-of-the-box. If it was made with some substandard components, it may not last as long as a card that can be traced back to LSI. Most of the listings I looked at say "OEM" in the listing title, which means no warranty. They may have different firmware and/or PCI IDs, but switching to the stock firmware has been covered here many times, so that shouldn't be an issue.
You might want to read my article here about the wide variety of "unofficial" products. Some can't even be determined to be fake by the companies that designed them (I give an example of Cisco in the above link).