For me there is no question, novels beat short stories hands down. I don't dislike short stories, but when I read fiction, I prefer to travel to a different world and then stay there for a while. Short stories don't have the same amount of time to build the world, nor do I get to stay as long. I have a similar struggle when it comes to writing novels versus short stories. I'm not trying to imply that writing a novel is easy, but I honestly struggle more with shorter fiction and I find myself losing interest when I try to write a new one or edit an old one. I'm not sure why I feel this way, but it seems to have followed me throughout my experiences with literature.