From the name, I can tell it heats the engine in cold cold weather, reducing warm up times, but I'm not sure how useful it is. It says it's supposed to reduce wear and tear but does it really? Can someone shed light on this?

The real benefit on engine wear is that it keeps the oil warm enough that it flows well and will lubricate immediately after the car is started.

The most wear of an engine occurs when it's cold. Because not every part expands as quickly as another part. That's why cab drivers can make so much more mileage / kilometers than the average driver. I've read there are cab drivers that made OVER 1000000 km with the same (first) engine !! (=625000 miles)