Any suggestions on an accurate (I mean dead on accurate every time) T Square ?? I have a drywall square, it's great for cutting sheet rock, but it is NOT accurate. A good framing square is awkward (at least for me) and not as accurate as I want.

I'm looking at the Woodpeckers 24" aluminum T Square for $130. Any alternates or suggestions would be appreciated. Personally I think its a lot of money, but my goal for the next few months is to master the art of 'square'. What do you all use for reference??

BTW: I tried to search the forum to see if this topic has been discussed before, but the search engine will not recognize the T by itself, and square brings up every third post.