It depends on where you go. If the police drag you out of the woods kicking, screaming, and bleeding and you wind up being involuntarily hospitalized, it sucks. If you go to the ER and say you're not safe because of psychiatric illness it's not that bad. There's a lot of free time. The place I go to for voluntary hospitalization typically has a day like this: Wake up, have breakfast, morning group (stuff like how you slept, how you feel, goal for the day), then do nothing for an hour and have another group, have lunch, more free time, another group/go outside if it's nice out, have dinner, visiting hours, then bedtime. You stay as long as your insurance will pay for (typically a week). Involuntary hospitalization is pretty much meals and free time. Either way you're going to be checking in with the doc once a day, maybe less.
The only change in how people treated me is now when I'm having a hard time my family asks if I need to go to the hospital.