I cut on a regular basis and haven't filed a chain of my own in years. I change when they slow down, sharpen them with my grinder at night. I don't even think I own a chainsaw file other than the one that's by my sharpener to show customers how to properly hand sharpen a chain if they desire. I doubt that I could actually get a chain sharp with a file these days. I get absolutely zero pleasure out of hand sharpening a chain.Whether U choose to sharpen in the field or at home is a personal choice, but I can not imagine anyone who cuts on a regular basis not knowing how to sharpen their own chain!
I pack two sharp chains and the one on my saw if I am in the field. I don't buck in the woods and move them in log length, so I rarely even get to one of my spare chains in a day.