Unlike Wool blocks, shears do not mine carpets faster than fists, and do not benefit from the Efficiency enchantment when doing so. This is not a big deal since carpets break quickly anyway, but it would be nice if this behaviour was changed to be consistent with wool blocks.

To reproduce, just obtain an Efficiency V pair of shears, go into Survival mode, and break carpet blocks with fists and the shears; both will break the carpets at the same speed.