Never climb a 9 mm thick rope using a Grigri. Start only from 10 mm as is written on the device. Because filth or anything might stick to your rope the Grigri not always closes with those thinner ropes. A very good and save device though.

pros-- It feeds rope nicley, lowers, great for projects, and catches well.
cons--expensive, heavy

Working as a climbing instructor I have to train people who are new to climbing. Grigris are an excellent tool to help train how to belay correctly. The fact that it is auto-locking makes it almost fool proof, but it is always a good idea to implement casualty knots.

While the GriGri may be a little hard to master, once it is done it is incredible. I lead climb with somone much heavier than I am, so the auto-locking mechanism saves me from being ripped the extra foot into the air when I am belaying. On top of this, because I don't have to worry as much about locking off, I can pull in more slack, making my partner's fall shorter. Despite what people say, lead belaying with a GriGri is actually pretty easy. Just make sure you know how to use this tool before going off and belaying somone on it

I really like this device. I'ts easy to use and makes your friend's project route that much more liveable. I've use as small as a 9.7-mm rope with it and it still works fine -- just have to give it a little break and it locks. Infact, I think it works better 'cuz it allows for a dynamic catch. It is a little harder to give rope at first when you start using this, however, there are some good methods to doing it quickly.

<p>This is my problem with people and the grigri and for all autolocking devices
for the casual climber -- this totally gives a false sense of security. Slow falls, thin ropes, and light climbers can be a dangerous combination while using this device. Do some reading and get some instruction when you first use this. If you drop someone you could seriously injure them and you just don't want that to happen, so be smart.