In short, yes. Read speeds are important to the person who is waiting for a transfer to complete. Long transfer times can lead to a loss in productivity. Write and bus speeds will become tantamount when shooting pictures and video. If a card is not fast enough, it can lead to dropped frames in video. And, if your card is not specced highly enough, your device may not work properly. Make sure that the specifications of the card you buy match your device’s requirements.