It may not be as accessible as the (dead simple) RAM hatch found in the 27" iMacs—but still, this is a major win for upgradability over all the 21.5" iMacs with soldered RAM that we've encountered in recent years.

Before moving on, we take a moment to scope out the silicon these memory modules have to offer:

SK Hynix H5AN8G6NAFR-UHC 8 Gb DDR4 SDRAM (4 × 8 Gb = 4 GB per DIMM, 8 GB total)

Ablic (formerly Seiko Instruments) S-24C04A 4 Kb Serial EEPROM Memory