Those bobbin alerts would be really useful if they gave an estimate of how many inches of stitching were left - like my car does by letting me know how many kilometers I can drive with the fuel in the tank.
I can see my bobbin, and it's like a game to see how close to the end I can sew. A perfect win is when the end of the bobbin thread comes up when I pull the fabric away at the end of the seam. :)