That's the idea, yes... once the device has scanned a card it shouldn't have to do so again or at least the process shouldn't take as long as it would do initially. Not sure about hot swapping while the device is running. Suppose you could do a library scan if you did again, should be quicker given that its already scanned it in the past.
Am not sure what cards people are recommending, a good brand should perform the same as the rest although in the solid state drive world Samsung is currently doing well, expensive though... some are saying that its best to buy an SD card reader to upload files onto to then use in the device... A&K say that its best to use their program to access their products. So I'm assuming that people are using an SD card reader with the iRiver software and writing files in that way and that it works well for them.... would otherwise have assumed that A&K's advice meant using the device with the software for the best results. Testing the device via drag and drop it read the individual file names and the album/bit rate etc in the play menu but didn't show the title or artwork in the main album menu, no artwork in general, am worried about people saying it has a liking for 500x500 sized images as mine are varied.
I doubt iTunes would work.