I don't know what Caged Heart is, but I know that I couldn't get into OISTNB because the main character seemed too weepy. (Of course I watched up until the period burger and promptly threw up all over my computer desk. The joy of watching something when you're dealing with a stomach virus.)
Piper is intentionally completely awful, mostly because she is an awful person in real life too. Jenji Kohan used her character as something of a Trojan horse, where she was the way she would be able to make a show about minority women in prison. Really, Piper's not even an important character, she's just there for the story to progress and be able to tell the other inmates stories.
I had trouble with the first two episodes as well but have really liked it after that. it is funny the sexy bits get toned down at that same point and it gets funnier.
