I can't vouch for the author at all, but this seems like a nice detailed, technical look at the difference between the two.

TL;DR the 212CD is very good at what in biology would be called "sit and wait predation". It's designed to sneak into an ocean floor crevice and hang out there, possibly for for weeks until something comes by, and then attack it. The Hanwha offering, on the other hand, is less superlatively stealthy and maneuverable, but is much more flexible, allowing missile launches and likely having a much longer range.