OCModShop posted a review on the Vantec SuperSpeed USB 3.0 Card

The Vantec SuperSpeed USB 3.0 card is definitely fast. It can supply enough bandwidth for SATA hard drives to work at their full potential, and works much be tter than the chipsets on many motherboards. While testing USB flash sticks in our test labs, we have discovered that the quality of the chipset on the motherboard greatly affects the USB throughput. Even if you don't need the extra bandwidth right now, the NEC D720200F1 chip on the SuperSpeed card provided the best performance we have seen on all of our existing USB 2.0 devices. So if you think you're not getting the most out of your USB devices, then it's probably your motherboard's USB chipset and you may want to upgrade to the new technology.

I would recommend Vantec's SuperSpeed USB 3.0 card to any PC enthusiast, but I have a few improvements for the next generation of cards

Ventec SuperSpeed USB 3.0 Card Review