I think what most people don't realise is that just because this show is helmed as an "adaptation" of La Casa De Papel, fans of the original assume it's going to be the EXACT same, which is completely untrue. While the characters' names, places, and plotline share the same origin...the actors and the character personalities are widely different. Personally, for a season that is just 6 episodes long, the depth we reached with the characters were completely satisfying. The original was way longer and much more expansive background-wise than this version. So tread wisely. But after all is said and done, I'm happy that this wasn't a complete copy paste of the original, because where's the fun in that?
The actors playing each character fit seamlessly into their given culturally accurate roles. Please remember this is set in Korea and differs wildly from the Latin culture that was the set of the original, so creative liberty is justified.
Personally, I think it would be a disservice to the creators of each version to be compared and ripped apart, because they're each unique in their own ways. If you're a die-hard fan of the original, it's your loss if you are beginning this show expecting a complete retelling because once again ADAPTATION DOES NOT MEAN COPY PASTE.
Also, the casting is just SPECTACULAR and with the unfortunately short length of the season, I'm looking forward to a much deeper exploration of the characters' respective backgrounds in the second half. Definitely a fan of this version too.