Now days most climbers tend to place far more cams than nuts, only placing passive protection where cracks are too tapered and aren't parallel enough for cams. This is one of the main reasons that nearly all of our OutdoorGearLab testers climb with DMM offset nuts, because they work the best in places where cams don't.
The DMM Alloy Nut has an anodized heads to more easily differentiate sizes. The slightly rounded corners help with cleanablity. These nuts have decent overlap in their sizes so you won't get stuck too often with in-between placement. The best aspect of DMM Alloy Offsets is their distinct and dramatically offset sides that help them fit perfectly into pin scars where many other nuts might only be marginal. This is apparent in older climbing areas such as Yosemite, Zion, the Adirondacks, Index and Lovers Leap and in newer climbing areas as well. They fit in non-parallel-sided cracks well and they also sport cutouts on either side that help them place into irregular and highly textured cracks with confidence. In side-by-side tests DMM Alloy Offsets gave the most bomber placements in the widest range of cracks of any nuts we tested, from granite to sandstone. The cable on the top of the nut is recessed into the head, thus adding to your placement options by keeping the cable from getting in the way.
Because of its offset nature, the nut doesn't rotate if you yank straight up to clean it, causing the cable to kink. The cable is glued into the head of the nut, also leading the cable to kink and eventually unravel. The problem isn't as bad as with DMM's brass models, but it is still a problem. Unfortunately DMM doesn't produce smaller sizes in the aluminum version, which keeps them from being a stand-alone set of nuts. The Alloy Offsets are the most expensive nuts we tested.
For aid climbing these nuts are practically a must. If you are a cam-placing junkie and rarely use nuts then you will probably enjoy these nuts more than others due to their ability to excel when cams won't come close.
At $16 per nut or $70 for the set, these little babies are the most expensive in the review twice as much as some other nuts. However, if you are into aid climbing, especially in Yosemite or Zion, the DMM Alloy Offsets are nearly as important as your aiders.