if used many tee squares in my years of work, an have to say that this is one of the best i have used so far, accurate and reliable, even after knocks and falls. worth the money.
As an Adjustable T Square it does exactly what it’s intended for; however I required an Adjustable angle rule to create perspective lines on large canvases for painting. Problem solved by introducing a large nylon washer which allowed me to adjust the angle and tighten it so that it didn’t move.
I am currently building a balcony on my house and need to take and check accurate 90 degree measurements in awkward positions, this tool is making me wonder why it,s not a more commonplace tool as its making what would be a very awkward job very simple and quick,as I have only just started using this tool I can not see any downsides and I don't really think I will.