They both offer the Korean MMO specialty of Slog and Grind, so pick your poison. Blade and Soul seems to offer more customization (as in less classes inextricably tied to a certain race/gender) while Black Desert is more impressive on a technical level.
Yvelont Navarre
Parn Paparn
IC Blog for Yvelont: http://never-your-pawn.tumblr.com
OOC Blog: http://navarre-again.tumblr.com
Parn Paparn
IC Blog for Yvelont: http://never-your-pawn.tumblr.com
OOC Blog: http://navarre-again.tumblr.com