My rock gym has two of the True Blue auto-belay devices. (See this website for more information on the device itself: http://www.autobelay.com/
The check-off was simple:
1) Do not let go of the tether because it will shoot up to the device and then have to be retrieved;
2) Do not go around corners or try to go up a wall not directly below the device; and
3) When lowering yourself, do not bounce along the wall because it makes the machine bang against the wall and might damage it.
Yep, that was pretty much it for instruction.
I was given a harness that had a top loop rather than using my Camp harness which has a side loop. the reason for this is that the carabiner attached to the tether needs to go into the harness so it is vertical. The harness was a Camp Topaz Plus.
Climbing with the tether is just like climbing with a rope, except that you can't yell "take" and get a rest. In fact, if you let go of the wall with your hands and lean back, you go into freefall for a couple of seconds and then the machine begins to lower you. Once you're being lowered, it doesn't stop. You just go right to the ground.
Other than being startled by the freefall the first time, I found the lowering to be fine. It's slower than I usually do on a rope, and I could either walk down or just keep one foot against the wall lightly and let it lower me. It was a gentle drop.
What was exhausting was realizing that I could climb up again and again and again, without the usual break of belaying for my partner. After an hour I was sweaty and panting. This morning my left shoulder and elbow are sore from climbing so much.
I miss two things:
1) the social aspect of having a partner - there was no chatter, no laughter, no flipping anyone off who was talking smack about my climbing or lack thereof; and
2) the ability to stop, lean back on the rope and rest for a moment while I tried to figure out how to make a move on a route.
I ended up abandoning the formal routes after a while and just climbed. I tried to make all kinds of weird moves on the tether and found it worked fine. No matter what I did, it held me, the tension stayed steady and I felt safe.
So I guess I will be climbing using the auto-belay. I think I might actually get stronger on it quicker, because I don't have the luxury of standing around and bullshitting after I have just climbed.