The situation with NAND flash has been pretty disappointing, I think; in the quest for more capacity, manufacturers have been sacrificing other desirable aspects of storage, like write endurance and data retention. In particular, 3-bit and 4-bit MLC are becoming the norm, and they are both slower and less reliable than older 2-bit MLC or SLC, while requiring more complex error correction and bad block management. The relatively increasing fragility of flash storage is never mentioned, and many people don't find out until it's too late --- because the typical consumer only focuses on capacity.
I still miss the days when SLC was the norm, and you didn't need complex error-correcting-codes and bad block management. Now SLC is considered "high-end", even in enterprise applications, and becoming rarer to find, while 2-bit MLC, which used to be considered the inferior, consumer-level grade, has also become more difficult to find and a "professional" feature. Considering that endurance and retention decrease exponentially with each additional bit-per-cell while capacity only increases multiplicatively, the tradeoffs don't seem quite so great.
I'm not saying it is a bad thing if you understand the tradeoffs and can work within them, but what I'm getting at is that a lot of consumers unfortunately don't.
The extreme endurance torture tests that get reported often don't tell the whole story either - the more flash cells are cycled, the "leakier" they become and retention goes down significantly. Figures I've seen for SLC are 10 years retention after 100K P/E cycles, earlier-generation MLC 5 years after 10K P/E cycles, newer MLC is 5 years @1.5~3K, TLC is 1 year @ <1K. Of course retention tests don't make for as interesting news articles as endurance ones since they're almost like watching paint dry, but IMHO they are just as if not more important, and manufacturers should provide warnings that flash-based devices are intrinsically unstable and their retention ability is measured in years. "Bit rot" is a reality with NAND flash. I only hope that people who think they've "backed up" data onto used SSDs, memory cards, and other forms of high-capacity flash don't find that much of it has literally self-erased and disappeared after only a few years.
I still miss the days when SLC was the norm, and you didn't need complex error-correcting-codes and bad block management. Now SLC is considered "high-end", even in enterprise applications, and becoming rarer to find, while 2-bit MLC, which used to be considered the inferior, consumer-level grade, has also become more difficult to find and a "professional" feature. Considering that endurance and retention decrease exponentially with each additional bit-per-cell while capacity only increases multiplicatively, the tradeoffs don't seem quite so great.