At best psychiatric commitment gives the illusion of due process and justice/accountability, the spirit/intention of the constitution is being violated. Most apparent is the violation of a speedy jury trial, the right to confront accusers, equal protection under the law, and to be secure in person without probable cause, going even further it could be considered a form of slavery or cruel/unusual punishment.
Prisons can actually be more comfortable because prisoners have access to commissary, sometimes jobs or training, limited use of technology, more physical activity, more privacy, often more books, and often times less abuse of power by the staff (this one is variable, but surprisingly true most of the time).
In a lot of prisons, prisoners publicly masturbate to the female guards and regularly make sexual remarks to them without facing any consequences; such behavior would result in severe punishment in mental institutions where most of the staff is female. Some prison units allow for prisoners to roam and socialize throughout most of the day, while some closed psychiatric wards have padded cell rooms with solid doors that seal shut.
The chances of you experiencing painful and disabling effects from forced drugging or getting dragged across the floor and body slammed to a table and needles shoved in your butt cheeks one a regular basis are far less likely to occur in prison (but if it does happen, psychiatrists were involved regardless). I would easily choose prison over a visit of equal time at a locked psych ward.