I got the new northern tool catalog and was looking through the tractor attachments and I saw a drag harrow rake and they say this can be useful for dethatching. I've seen guys using these to finish dirt, or put seed into dirt when preping a lawn. But never herd of them being used for dethatching. Any opinions? I know a power rake is the best way to go, but what about those large lawns where a tractor mounted attachment of some kind just makes more sense?