Not all of these types of pull behind harrows are the same construction, some you can reverse the direction of pull, or flip upside down for smooth. I have one of the originals, a Fuerst Harrow that I have had thirty years. I use it either in the most aggressive way and have iron weights hanging off the hind end. I use it breaking up manure clods in pastures.
Sometimes I use it in a paddock for "grooming it" and picking up debris that seems to migrate in there at times,including hay string. The weights I use are old bulldozer parts and old time window weights. If you go slow, have a chain longer that five feet from the tractor draw bar it works well for what I do with it.