the one in the tunnel is Balach he patrols it in one end turns and back through and keeps doing it until you send him off he loves it but if you forget and dont mind him he is back in there stopping the other from getting through.
you are right it is a load of fun and i think thats what training should be it builds a better bond... doing this type of activity is where positive reinforcement comes into its own ... we call it fungility and the heel work is fast pace and we make them move beleive you me they are all knackered by the end ...
however, not that i want to enter a discussion but to reach this stage you must have a good level of discipline and that comes for good correctional training.sorry i know not everyone agrees and it is just my opinion and my way of training and i get great results and fab dogs i can take anywhere off lead if i desire.