When I first began to use digital cameras that took SD cards instead of the larger CF cards, the dainty little cards proved quite unreliable. Not in a computer/electonic/data way, but mechanically. The thin plastic body of the cards tended to crack and split (even though I treated them carefully and wouldn't be caught dead doing something like dropping a card loose into my pocket) and worse, the write-protect tab would break off, also rendering the card useless. At least this left the cards readable, so no pictures were lost. This happened, repeatedly, with several different brands.
Sometime late 2010, I needed cards again, and bought a pair of 16 GB, 163x Delkin Devices cards. I chose them simply because they were on sale, and I hadn't tried that brand before. They have performed flawlessly ever since. I have no idea how many times they have been removed from a camera, inserted in a reader or computer card slot, then returned to the camera and formatted. Something over five years, 365 days in a year, and if I shoot I always download the cards at the end of the day, and I shoot at least something nearly every day. Most everything that found its way to this blog in the past 5-6 years was recorded by that pair of cards. Finally, earlier this week when I replaced "card 1" in a Lumix GX7 camera, it wouldn't seat properly. I got it out, and with close examination found that a bit of the housing plastic between two of the gold contacts had come loose. I managed to remove the sliver, and out of curiosity put it back in the camera, where it proved to work just fine.
But the handwriting was now on the wall. So, a quick trip to the B&H site, where I searched for SD cards, Delkin only. I found that 32 GB, 633x-speed cards were on sale for the ludicrous price of $15.99. Twice the capacity, and nearly four times the speed. I got a pair, and had to order a couple of other little accessory items to get the order up over $49 for free shipping.
When the cards arrived this afternoon, the first thing I did was put one in a GX7 and format it. Sure enough (I didn't use a stopwatch) but the format operation for the 32 Gig card took about half as long as the 16 Gig cards had taken. Downloading the several snaps of the old cards, using the Adobe DNG Converter, also went obviously faster than with the 163x cards. So the venerable cards are now put out to pasture, in a hard case for extra cards, where they will have a peaceful existence because I've never come near filling them, and now have twice the storage in-camera.