The M3 line with 256Gb storage had a single SSD NAND chip which made it measurably slower than the M2 series with the same amount. Although irrelevant for most

The M3 line with 256Gb storage had a single SSD NAND chip which made it measurably slower than the M2 series with the same amount. Although irrelevant for most daily work it was a regression which seems to be fixed in the M4 line. Even then, I presume such a bit of bad news would trigger people looking for 'the best spec' to buy the storage upgrade.