The stories you'll be able to tell. You can't make up what you'll see when working in psych. You will have the best stories to swap with other nurses, and except for those staff who work in ED (which is pretty much where half of the psych patients come from), no one will even be able to come close.
Professional development opportunities. You will develop great therapeutic communication and interpersonal skills that translate over to many specialties. You will keep up more of your medical skills than you think, since psych patients don't leave their medical problems at the door when they are admitted. You will become a master at injections and secure-yet-quick-release knots. You will know how to sedate a patient twenty ways to Sunday.
Worried about the technical skills getting rusty? Anyone can relearn how to insert a Foley...same goes for most tubes and skills. Nothing to lose sleep over.
Fewer blood and body fluids to deal with. Granted, sometimes the ones you deal with may be encountered in new and creative ways. But you're not going to have to deal with lines and IVs, and more than likely you will not be giving bed baths. You'll see far less blood, poop and sputum in psych. Vomit...well, if you work detox, you'll see more vomit. But even in detox, there's still less blood, poop and sputum overall.
Less family members to deal with. Most psych facilities limit visiting times, which means fewer demanding/entitled family members to deal with. So you're not going to be fetching sodas, snacks and blankets for people other than your patient (actually, you won't even be fetching them for your patient, but that's another bullet). And thanks to HIPAA, you may not even have to talk to them about the patient other than saying, "he's in the day room, I'll bring you there."
Opportunity to meet lots of people in law enforcement. Without you being the one in handcuffs, that is.
You're not a glorified waitress/maid. In psych, we encourage patients to do as much for themselves as they can. So if a patient comes to us asking for a change of linens, instead of making the bed ourselves, it's actually more therapeutic for us to respond, "Sure, I'll get you a clean set so you can make up your own bed, and then show you where to toss the dirty sheets." Patient wants a snack? "Here, let me show you where the pantry is. Help yourself." Patient spill something or make a mess in that pantry? "Hang on, I'll get you a towel so you can mop it up."
Try doing that on a med/surg floor and see what happens.
No call bells. Need I say more? OK, call bells may exist in gero-psych. But in most of psych, there is no such thing as a call bell.
You really get to talk to patients. It's part of our job! We're expected to chew the fat with them--that's one of our therapeutic interventions. No running around doing drive-by assessments and spending 15 minutes or less (out of 12 hours) with the patient because you're too busy juggling everything and anything. So if you're the sociable type, you'll enjoy psych. If you're not as sociable...work nights in psych where only half the floor is awake, so there's only half as many patients to talk to.
Dealing with your own difficult family members/people will become much easier. Seriously. After honing your interpersonal skills dealing with psychotic patients, patients who are acting out, patients with personality disorders, or patients who are hallucinating about an army of squirrels that are trying to to implant microchips in the entire human race...handling an overbearing parent, ornery child or a delusional boss is a piece of cake.
Job security. Not many people want to work psych for whatever reason. You'll have less problems getting a psych job than you will trying to get a job in one of the high-profile specialities that everyone else wants to work in. You'll probably make a higher hourly rate too. Also, psych nurses frequently get recruited...and you don't need to have 7+ years of experience to be targeted: have just two years and recruiters will start making advances at you. And this includes recruiters NOT in North Dakota.