Upload & Sell: On
I guess I have had good luck over my 6 year digital experience because I can't remember a card failure. But then I buy my cards, new, from established retailers. There are counterfeits and those can come through various resale sources. Note, I once bought 2 pricey Shure microphones on eBay to learn sometime (too much) later they were fakes.
However, I have run out of card space and that is more than inconvient since you lose the opportunity to capture that moment. But then if I had had card failures that would, certainly, influence my card opinions. I try to match the card speed and capacity for each camera I use but I don't "Pay Up" for a faster readout to my computer. My new 16Gb Sandisk is only good for less than 200 shots on my D800e but, even at 4 fps, I hope that will be enough for inanimates.
I mostly shoot dancers and some singers that move quickly. I just shot a Jazz singer in a night club-handheld no tripod allowed. Available light meant I set my D4 to somewhere around ISO 6400, F2.0 and 1/200 sec (upon observing successive frames it was apparent that the digital light source varied as to color temp and level). I used 10 fps because that is as fast as a D4 will go (FF/mirror down).
I shot over 700 frames woth a 200mm lens (or 340mm with 1.7Tc) becaise I wasn't allowed to get in front of the audience (house rules). Pretty much each frame was different and I picked 8 possibles and two heros. I was, certainly, thinking, framing and trying to put the AF box on the near eye. Nevertheless, many shots were not in optimal focus because this lady moved so very quickly and her expressions changed in an instsnt too.
But if there's a better way to cover such a candid subject I am certainly willing to learn. However, it's not anticipated a candid moment (mirror lag) and shooting 10 or 20, unposed, frames unless there's some camera that comes with a time machine as an accessory.