I had one for about five years. It was perfectly healthy, but for some reason it got infected after I moved to a different town. I got rid of it and never put it back in after the infection healed. I also broke one of my molars (OUCH) when I bit down on the stud when I thought I was biting down on a popcorn kernel.
Mine didn't hurt because I had the best piercer in the world. All of my pierced friends recommended this guy because he didn't use forceps and because he had an almost hypnotic manner, so much so that you didn't really know he'd pierced you until you saw the needle sticking out of your body part. I'd go to him again - as a matter of fact, maybe I will now that I'm back in my hometown for the holidays!
Aftercare is important. Stay away from toothpastes with peroxide in them. Don't be afraid to move your tongue around after the piercing - it'll just make it hurt that much worse when you do move it. Drink lots (and I do mean LOTS) of cold water in the first 48-72 hours, rinse with a solution of sea salt and water during that period (not table salt), take zinc and vitamin C every day, don't smoke, and the swelling will be completely gone. A properly pierced tongue should be completely healed in about 2-3 weeks.