Only if you have a very relaxed definition of "square"...
With the "squares"
touching at the bottom, I measured a 0.018" gap at the top.

0.018" gap is relaxed enough for me
Never had a problem using them on any woodworking tasks.

That kind of accuracy is not going to be easily visible on shelf alignments
at least.
I use them all time on box and drawer construction and never had any
noticeable problems, but as you say, we all have different ideas of how
"square", square needs to be
The item you have menioned looks like a worthy alternative however.


--
Regards,

Dean Bielanowski
Editor,
Online Tool Reviews
http://www.onlinetoolreviews.com
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