I'm neither but what my doctor usually recommends is something which helps with coughing for the day and something to stop coughing for the night, since, well ... sleeping when you are coughing your lungs out sucks.

Had a bad enough cough to be prescribed it once. Answer is: if you can't get any sleep due to the cough, you'll soon be too weak to fight what's causing it (or even to cough properly). Had been sick for 2+ weeks when I got the prescription, iirc only took it 3 nights. Once it bought me the sleep I needed to get my immune shit back together, I was feeling better in a couple days.

I'm currently on a codeine-based cough medicine and it has an expectorant in it to help bring up any mucus when you do cough because none of these medications completely eliminate it.

I personally only take it at night because I cannot function on codeine, but even then I still have a productive cough during the night.

These medications aren't (shouldn't be) prescribed to people with mild/moderate coughs. They're for people who can't sleep at night and can't get rest to fight off the infection (I was sleeping less than four hours when I saw my doc). They're for people who are coughing to the point of vomiting and injury (also me). So, generally people who are doing more harm to their bodies by coughing than they are by not coughing.