it wont affect the normal operations but abit so if you use burst mode often. also a high speed memory card won't do you much good if your camera's write speed is not as fast as the cards write speed.
suggest you borrow a high speed mem card for test. it made a difference for me (FZ3) I shaved 50% of savings speed from using higher speed sd card. every seconds faster means you're ready for next shots sooner. ;p when you're taking group photos, try telling the people to wait 2-3 sec for successive shots. :bsmilie:
The Kingston blue one is the same as Toshiba blue one, normal speed. If u want high speed, can try the Toshiba white one (high speed), it does make a difference, but the price is much higher, not sure worth it or not.
if you want a fast card, can try Kinston elite pro, it appear in either the blue or the rare white version usually cheaper than other brand as well hehe