This has been covered elsewhere, but I have never found a CF card of any brand or size that did NOT work on my 702. The 7xx boxes have a speed test so you can check CF cards (and external drives) to see if they are fast enough. As long as I don't try to jam data into a card faster than it can take, there is no problem. Maybe with a 744 recording 4 channels at 96/24 or 192/24 you'd need a fast card, but with my lowly 702 at 44/24 or 48/24, I can use any cheap card.