memory card speed for G15

Does anyone know if the G15 can take advantage of the faster write speeds available in class 10 and UHS-I cards?  I know there's not much point in moving to a faster card if the device the card is in can't support writing that fast.

And, if the answer is "yes," is the difference noticeable enough to justify the cost?  I'll be shooting mostly RAW+jpg and I don't do a lot of video.