I recently purchased a set of Wild Country Superlight Rocks mainly because I was impressed with the ability and ease of setting the original WC Rocks, at least in basalt.  However the Superlight Rocks go above and beyond its predecessor.  Here's the good:

• Combines the parallel crack profile of the WC Rock with the offset profile of the DMM Offsets (in fact by eyeballing it, the WC Superlight Rocks #4-6 match the offset profile of the DMM Offsets #7-9)
• Surface area of either profile is the roughly the same, eliminating a preferred orientation for setting the nut; just turn it 90 degrees
• As the name states, these are Super light
• Single wire eliminates swage for closing standard nut wire loop
• Attached wire prevents the nut from moving, sometimes allowing you to remove the nut by pushing it out of a placement
• Thin profile is great in very shallow cracks or when you need to eventually use the location of the placement for your hand or foot

Unfortunately there's always drawbacks to a product of this nature, including:

• Less durability due to the single wire design
• Costs around 50% more than a standard nut
• It only comes in sizes #1-6, making it a replacement for this limited size range, or a supplement to a full set of nuts
• Smaller surface area may be problematic for soft or friable rock
• WC Superlight Rocks #1-2 have a load limit of 4kN

These nuts rock and give you a lot of freedom for placements that other nuts simply do not match, however generally they should be thought of as a supplement and not as a first nut purchase.  But if you carefully match these with other nuts, they might just be able to replace your smaller sized nuts, at least in hard, non-brittle rock and/or on alpine routes.