If you like old school Claremont it's probably worth reading, but not for Karen.
The original line-up was built along X-Men lines, where everyone fits into particular archetypes and have fairly narrow powersets that, while useful on their own, are more designed to compliment each other than they're designed to stand on their own. There were some interesting mysteries (more like unanswered questions), especially early on. The setting (a small town called Crossroads) was one of DC's more interesting places, the supporting cast was intriguing and fun, and there were some good guest appearances from the more "standard" side of DC. The overall premise was pretty great, sort of like a reverse Exiles. And one of the characters was non-binary decades before that became part of the national conversation. And the art was always top notch, especially by the standards of the mid 90's.
But I don't feel like Karen had her best showing there. She was brought in to replace one of the original members and never really seemed to fit; everything from her powers to her costume felt out of place compared to the others and she never really seemed to have a viable reason to be there. She was a round peg being forced into a square hole and this was back in the "Atlantean origin" era so Karen wasn't at her best in the first place. She would've fit the title better these days, with her multiversal refugee origin.
And the book was painfully over-written in classic Claremont style. Which some people like and some don't (I personally don't). I think the book is worth reading if you can get it for a reasonable price, but don't get it for Karen, you'll be disappointed.