I'd always just used Lightroom to get the images off the card onto disk. Did a photo workshop recently where the instructor said he always used the computer's copy paste functionality to move the images, then added them to Lightroom once they were on the disk because it was significantly faster overall. Tried it and was blown away at the difference. Making the preview images eats up a lot of processor power and disk, as does copying files, and at least in this case, by doing the two consecutively you save time versus concurrently. I wouldn't have believed it if I hadn't tried it.