Ethics in Justice Administration

Mental health issues abound in the corrections system.
Due process is sometimes challenged most when a criminal defendant is mentally challenged.
The following case involves a defendant whose capital murder case has been before the US Supreme Court on two occasions.
The attached opinion (see below) is the most recent. Much time, effort, and expense has been spent on this case both from the prosecution and the defense.
After reading this opinion (see link below), tell me whether or not you think all the effort by all the attorneys, experts, court personnel, and judges has been worthwhile.
What has been gained and/or lost by the prosecution.
What has been gained and/or lost by the defense? What has been gained and/or lost by the criminal justice system.