It would be nice if it stayed locked by sliding the button. Holding your index finger on the trigger the entire time is not cool. Will not ever purchase again.
My dog enjoys being able to "bounce around" and cover 3 times the territory I do on walks. Love the index finger trigger control; works better than a thumb stop.
Having the trigger protrude and standing proud on the hand grip is a great design feature - it is easy to engage if the dog lunges forward. Webbing instead of rope eliminates jamming.