Bought this for an old Pentium 3 system that only had USB1.1. I fitted the card into an empty PCI slot without any issue and tested it in both Puppy Linux and Ubuntu by transferring some video files to a Flash Drive. Transfer rates were much better than USB1.1 though that is to be expected. However I'm not sure how they would compare with a native controller on a motherboard as I didn't benchmark them.
One positive is that I didn't need to provide a driver for either Puppy or Ubuntu operating systems as they both detected the card correctly. Drivers are provided for Win98 and others but I haven't tried them.
The one disappointment was that I have a wireless keyboard and mouse that use a USB dongle, and I couldn't get the PC to recognise this at startup so I had to leave it in the USB1.1 slot. Once booted you could move the dongle to the USB2 port and it does work. Note that this isn't an issue with the product but with the PC. I just included this info for anyone buying it for a similar application.
In summary this product is cheap, well packaged and works well, I can't faiult it. I'd recommend it as an easy and cheap way to add additional functionality to an old PC.