Hello,
I have both devices and use them for climbing and scrambling. The ATC-guide is my main climbing belay device. Excellent for climbing as it deals well with different diameters of rope. I often use it in the self-locking mode (i.e. attached directly to the anchor) when belaying seconds. There are a few reasons I use them climbing:
- on easy ground they allow two seconds to climb in parallel (on seperate ropes at the same time) as long as you're on the ball juggling the ropes
- don't kink the rope like an Italian hitch can. This can be a right pain on big climbs/scrambling routes
- self-locking feature means that I can belay safely with one hand whilst taking photos/reading guidebook etc. with the other
- I regularly lead all the pitches on long mountain routes. There's less physical effort involved for me in lots of belaying with these devices
The main reason I wouldn't use them underground is that if someone is hanging in space and unable to get their weight off the rope it is much more difficult to lower them to the ground than with an Italian Hitch (or an anchored Petzl Stop). When connected directly to the anchor the ATC-guide and the Reverso lock and you have to release them by weighting the back of the device with body weight etc. This can be quite awkward. I think that it's more likely that I'll need to lower someone hanging in space when I'm caving (for example if a ladder snaps or the climber is totally exhausted) than it is climbing. Secondly, I'd never have two people climbing a ladder at the same time so that removes one of the reasons that I use them above ground. Finally, I don't think I've ever belayed anyone up 500m of ladder in a day so I'm less concerned about making belaying physically easy for myself and the rope getting kinked. Belaying with a Petzl Stop fixes the problem of kinked ropes and also gives you the auto-locking help whilst still allowing you to lower ladder climbers.
If you're interested in the differences between the two devices from a climbing point of view have a look at this: http://www.orionmountaineering.com/phpBB2/viewtopic.php?t=26
Cheers,
Jules.
