I have a few of them, and all are top quality. Their accuracy is comparable to some vintage Starrett layout tools that I own. But with the bodies of the Woodpeckers tools typically being aluminum, they're not as rugged. That doesn't bother me personally, though, because I always handle my tools with care, and no one else uses them.
If I shop for a square at a big box store, I always have to test a bunch of them in order to find an accurate one -- and often I cant find a single good one. For example, I was recently trying to buy a good speed square. Most of the pretty anodized aluminum ones were accurate on the 90-degree angle, but they were all off considerably on the 45-degree angle. And the plastic ones don't even have good straight edges. But my little Woodpeckers Delve square
is dead on, so I still use it even when I'd prefer a larger speed square.
Rulers have similar issues -- the ends usually aren't aligned precisely with the scale, even if the scale is accurate. A stainless steel meter stick that I bought at Woodcraft, and wasn't particularly cheap, didn't even have parallel sides -- the danged thing had a taper to it. So I invested in one from Woodpeckers, and have never regretted it. All my Woodpeckers measuring tools are accurate to within the limits of my testing capabilities, in every dimension.
Being made in the USA, and subject to serious quality control, they're bound to be substantially more expensive than your typical Chinese import stuff. But time is money, and you can waste a lot of time if you rely on inaccurate measurement tools. I've finally acquired enough vintage Starrett & Lufkin tools, complemented by a few Woodpeckers tools bought new, to make almost any measurement I need. My big-box measuring tools now get used for rough work only.