The profile of the Black Diamond Nut Tool is slightly above the pack for squeezing into thin cracks to retrieve smaller pieces. The curve along the length of the tool helps with tapping pieces from above as well as giving the ability to hook cam triggers effectively. The BD nut tool is also one of the toughest on the market. This is the best nut tool at opening beer bottles (the end fits over a bottle cap perfectly).
The only and primary drawback to this nut tool was the fact that it was one of the most uncomfortable of any we tested. It bruised and cut our hands badly enough that on long routes we would look for a small rock to carry to help clean buried pieces. Another dislike, but not nearly as pressing, is the fact that it also lacks a built-in carabiner, forcing you to dedicate one to clipping it in with. This makes its light weight of 48 grams somewhat misleading.
Black Diamond makes a good functional nut tool for those seeking the absolute best price. It is great for those getting into traditional climbing and not wanting to spend more money than they have to get something that works. It is great for any free route and it will get the job done on aid climbs. The weight saved from not having an extra palm-protecting piece of metal could be a benefit for those on colder alpine climbs and wearing gloves most of the route.
Being one of the cheapest tools on the market certainly counts for something. However, the fact that this tool is painful combined with the fact that you need to dedicate another carabineer to clipping it into your harness decreases its overall value.