A reciprocating saw is known by a few different names; sawzall (which is a Milwaukee brand name), sabre saw, and a demolition saw. I usually call it a demo saw.
The reason that it’s called a demolition saw is because it’s not really a precision instrument and is meant to cut deeply and quickly through construction lumber and nails (as long as the blade mentions that it can cut metal).
That being said, I use my Porter-Cable PC75TRS 7.5 Amp Reciprocating Saw to take apart pallets. It does a great job at that in combination with a Lenox 20572-656R 6″ 6TPI Wood & Metal Cutting saw blade. It uses a twist lever to change out the blades which is great because I tend to change out my blades often for different applications.
It does get pretty hot after just a single pallet, which tells me that this is a light-duty tool, but aside from the discomfort of a hot tool, it has never let me down. Full disclosure: I’ve taken apart dozens and dozens of pallets.
One time I cut apart an all aluminum gazebo with this saw. That was pretty fun.
To summarize; pretty great saw, plenty powerful for light-duty work, but gets a little hot.