I use the ball launcher a lot! Great way to have then burn off some energy. I make sure it is on softer ground - or here where I live, icy/snowy roads, where my boy can skid to a stop, so easier on the joints, or grassy dirt during the summer.
Another thing I do to maximise running distance and minimise sudden stops is use two balls: I launch it one way, Gryff brings it back at full out run because he knows I have another ball ready to go, tell him to out as he approaches, then turn 180 degrees and launch the other way. I hurry to pick up the dropped ball and get ready to launch it again the other way for when he brings back the second ball - etc.
Twice the distance covered, full running in drive, half the stops/starts. Love it! (So does he!).