It's really frustrating watching everyone in this thread refer to brand names instead of tool names. Yes, the name Channelock is synonymous with tongue and groove pliers, but they make every other kind of plier under the sun. As for Knipex, yes, they make widely known waterpump pliers that are great on pipe, but they are also widely known for their pliers wrench (to which the subject Klein tool is very similar) with smooth, parallel jaws that aren't worth a damn on round pipe.
Unfortunately, the subject tool has a very similar design to the pliers wrench but has a reconfigurable jaw that allows it to function on round pipe, so that adds to the confusion. In short, this is a tool designed to function on both square/hex fasteners/fittings with parallel flats, as well as round pipe and round fittings by flipping the lower jaw. Therefore, it must be compared to something like a pliers wrench (as well as adjustable wrenches) but also to tongue and groove or waterpump pliers (and pipe wrenches for that matter). To pick one other the other and say this tool performs better for worse is missing the whole point.