18.2 brought better animation, for one. You can drastically see the difference in Jenny's scenes.
The scenes themselves are actually coherent and have a purpose. Prior to 18.2 she really didn't have a good storyline. The MC just peeked and perved on her while "buying" her panties for Somrak until he got to screw her. She didn't have anything to say. Now, she actually seems like a person. Her diary entries as the story progresses give you an idea of what she's thinking, from being frustrated that she hasn't gotten laid since breaking up with her boyfriend at the gym and ending with her having conflicting feelings about the MC after everything he's done for her.
She actually isn't as much of a bitch at the end of the current arc as she was at the start. She's the dominant one in the relationship and has full control of how much the MC gets, with him only really getting one chance to take the initiative on the couch. Every other time, she's in control. Also, she's a CamGirl having sex with one person but that doesn't make her a whore. Whores are screwing everyone.
Jenny was too similar to Roxxy with the "Bad Girl With A Heart Of Gold" story. Roxxy was already fleshed out so Jenny got reworked. Also, Jenny isn't finished yet. Odds are, more is going to be tied into the main story of the MC's father. Debbie will likely have new scenes as well, if her story isn't reworked at that point.