Yeah, TLR Darkness has far more plot (and "plot") than the original. At least it manages to have an actual storyline rather than just being a generic episodic ecchi harem series, since most of the cast is a one-trick pony, and Momo's plan to make every single girl out there fall for Rito leads to what you could call character development... even if it mostly amounts to them falling in love with him, or at least not wanting him dead.
Still, you'd better prepare for having 90% of your screen taken up by Swords of Concealing Light, because Darkness is lewd.
are the swords of concealing light in the BD release?
asking for a friend