rick wrote a review of Sterling ATS Belay and Rappel Device on October 10, 2011
Over my forty years of climbing I have tried many different types of devices, and this is the best one I have ever had. This device is the Leathermans of devices, so much functionality in one device. It is the only thing I carry on my harness anymore.
Rappelling: I really like the deferent friction modes as you are rappelling. When I get to a steeper part of the cliff or an over hang I just put the rope over the hyper horns and have a very smooth and enjoyable trip down, kid of like down shifting my Ford pickup.
It dose take a large round stock carabiner, to have a smooth ride. I tried one of the small Mammut Element key lock screw gate carabiner, and a standards SMC, they have to tight of edges. The Petzl M35 Sl Pear shaped carabiner works very well.
Belaying: I found placing the curve towards the belay carbiner, worked better than the curve away from the belay carabiner. When the curve was away from the belay carabiner, it had a tendency to stick. But with the curve towards the belay carabiner it floated better, but there was still plenty of breaking power. It kind of handles like a stitch plate, so having very tight belays was a little harder they a traditional ATC, but facing the large hole end on the top side of the rope made a handle that made it very easy to pull it away from the belay carabineer. The ATS it the best lead belay device, I have ever used feeding the rope out was very smooth, and a lot quicker than a traditional ATC type device.
Auto Belay: This is the best auto belay device I have ever used. Over the past few years I have tried, the B53, Reverso, Reverso 2, Mammut Vader Alpine, Black Dimond ATC guide, and non of them works as well at the ATS. But the key is to use a small carabiners so the device can hinge in the small hole. Connection the break carabiner can be a little difficult, you need a large long carabiner. The Petzl M35 was just not long enough, I used a old very large round stock parabiner. Like the Rappelling, a round stock carabiner works the best.
The best think about it is you can easily feed the rope out, by pulling on the large hole handle, but it still auto breaks. No other device I have used made it so easy to feed the rope out, when it was not under load.