I was first introduced to the many uses of the margin trowel fifteen years ago on a heavy construction site. I left the job but have carried the tool on every job and project ever since. When I moved to a desk I threw the tool into my tool bucket and still use it for just about everything.
The trowel is a simple piece of flat, quality steel attached to a wood handle. You can use it to finish concrete, set mortar, sling stucco, lay tile, scrape, pry, chip, hack, or cut anything not tougher than high-carbon steel. It is especially effective for cleaning other tools, such as shovels, concrete trowels, bbq’s, and garden implements. With only a modicum of care it will last for years. If you’re foolish or careless enough to permanently bend it then shame on you, but you can get another one for about $10.
It is superior to others because it’s cheap, reliable and robust. I prefer the feel of a wood handle to rubber, although the wood handle will chip if used as a hammer.