Used in belay mode
A couple months later, I ordered a petzl freino and have been using it regularly as my belay carabiner. Since it's a bit heavier (85 g), it is mainly for cragging. It is designed to use with single ropes to increase friction when lowering or rappelling. It works especially great with a gri gri or any other belay device. The 'mini' carabiner on the side of the device is easy to use and greatly increases the friction for descents. It works great for lowering heavier partners and also while rappelling. I wouldn't recommend using the additional friction 'mini biner' while lowering partners that are the same weight or lighter, as their descent can be a little bumpy when that amount of friction is used. In these circumstances, the carabiner can be used as your standard locking carabiner. I used it the other day when I rappelled on a single strand with my gri gri and it added a significant amount of friction that ultimately helped me feel safer while rappelling.
The carabiner is a bit awkward to put on a belay loop or gear loop when a gri gri is also on it. It seems like the gate doesn't open wide enough when a gri gri is also on the carabiner. Additionally, the auto-locking system may contribute to this awkwardness. The carabiner also needs to hang on just one axis, otherwise it hangs in a less than streamlined way. This results in a little bit of extra fiddling when getting the carabiner situated on a belay or gear loop.
Bottom line: This is a great piece of equipment to increase friction and ultimately safety. I wish I had one in Thailand!
Used in rappel mode