This is the thread for more in-depth discussion about Cabernet's personality, relationship with Dent, storyline, etc.
Personally, I love Cabernet as a rival. She is two cups of crazy mixed with one cup of adorable and one cup of woobie that's blended into a zesty rival with a refreshing taste. Ok, I'll cut the cooking references. She's Best Wishes' Harley or Urara, that really weirdly rival that's angry at one of the main characters and has made it their life's goal to beat them, being supremely entertaining doing so, though she distances herself from the first two because she has a legitimate reason to be angry at Dent since his arrogance and attitude made her give up on her dreams to be a trainer. She's highly entertaining as a character.
As a rival, I actually really like the dynamic between her and Dent. I don't really mind that she's not that good at sommeliering, because I kinda feel that that's the point. She's trying to become a sommelier solely to get back at Dent and it's holding her back, because in her mind being a sommelier is about trashing the relationship between Pokémon and trainer, which she does to Satoshi upon meeting him. It's fun to see that she seems to learn from Dent that there's more to sommeliering than that and that it's actually about strenghtening the bonds between human and pokémon. I could see her character ending one of two ways, either she'll become a better sommelier thanks to Dent or, and I think this is more likely, she'll turn her back on sommeliering because she'll forgive Dent, and we'll see her in the League.