Unless you're that lady on My Strange Addiction, the main benefit to being a vampire would be the whole immortality thing. The drinking blood would be a drawback.
However, by the end of Louis's story, living for centuries starts to seem like a drag. You get to watch all your loved ones get old and die. When you have all the time in the world, it's hard to appreciate what you have. And some people hold grudges for eons. There is always a catch with immortality, and Interview with the Vampire details the pros and cons in full.
There are a lot more cons.
Questions About Immortality
How does Louis's view on life change when he becomes a vampire?
Why does the boy want to become immortal, even after hearing Louis's story?
How does immortality influence a vampire's behavior? What things do they do that they might not otherwise do if they were mortal?
Is a vampire truly immortal? What can end a vampire's life?
How does the concept of time change if you're immortal? What becomes important to you if you know you'll live forever? Does this help explain any of the characters' actions?
Chew on This
Immortality isn't what it's cracked up to be. The whole novel is one big rant against immortality. It's basically tear after year of suffering for all eternity.
On the other hand, maybe immortality isn't all that bad. Louis gets dealt a bad hand: he has Lestat as a master, and he's stuck in charge of Claudia. The vampires at the Théâtre des Vampires seem to enjoy immortality. Of course, they're soulless evil creatures, at best, so…