I agree with Willum re use of the card in the KN7000. I have found that I have begun to use the cards with card readers with my PC's quite a lot and I do notice the improved speed when I am moving large files. The cards have replaced the zip drive that I previously used to move stuff between computers. The speed of the card could be important to you if you use the cards for purposes other than just the KN7000. There is also a time improvement in doing backups of the cards using a USB 2 card reader. Not sure how the Song Manager does with higher speed cards. I don't use the Song Manager.