Originally posted by RockvilleBob I just do not want to spend extra for a card with faster capability than the K-3 can write.
I've got some Sandisk Extreme Pro (SDXC UHS-I) cards, and use them when I need snappy write speed doing bursts with the K-5. I've found that there is a real, noticeable difference between the Sandisk Pro's read/write speed in camera, compared to other Sandisks like the Extreme's and Ultras that I also have a few of. To test it out without spending a lot of money, just buy a 8GB card and give it a go. When I get my K-3, I'll be populating it's slots with Extreme Pros, probably 2x8GB.
There are some comparative tests on SD cards in these forums, and on the web.