The Silverado Hybrid uses the same heavy-duty hybrid drive system found in General Motors' full-sized SUVs. The system greatly improves fuel economy in city driving. Highway fuel economy is only slightly better than the non-hybrid truck, though.
For the most part, you can do whatever you would do with any other big truck, although the added weight of the hybrid drive system reduces the truck's maximum towing capacity somewhat.
The fuel economy figures in this case also apply to the GMC Sierra Hybrid, which is essentially the same vehicle.