I forgot that I had ordered the woodpeckers version, and it showed up about the same time as my TSO square.
The woodpeckers is very well made, but it requires that you take another square, and square it to the track before tightening the nuts.
The TSO square has a spring clamp that tightens it dead square to the rail EVERY SINGLE TIME all by itself!
Shortly after trying both - I gave my woodpeckers square to my brother in law to use on his Dewalt track saw.......