What Tom said about ExpressCard. The slot has a single USB 2.0 connection and a PCIe 1x connection. The device can use either.

The class 10 rating isn't quite the same as the lower numbered classes. The SD docs say that the class 10 speed is only for when the card is not fragmented at all and for sequential write. The lower classes are rated against a performance curve. Its in the specs if you're curious enough.

I'd be wary of Kingston. Read this article about counterfeit and authentic SD cards. You'll see that certain manufacturers are favoured for performance/price due to certain factors like whether they actually manufacture the chips themselves.