I did it a few weeks ago, and I'm not really seeing the advantage vs the airport.
You print the tag at home, fold and insert it in the plastic holder, and go to the airport. At the airport you go to the bag drop line where you still have to do the ID and I think BP as if you're checking a bag and they're printing it. It was at BUR, so it's not like there's ever much a of a line at check-in anyway. Maybe at a busier airport there will be people checking in for multiple flights and a long line at regular check-in and a short one at bag drop.
ETA: I realized I've done it recently at both BUR and LAX and it was about the same at both, but not much faster than if they print the tag.