Sizing Accuracy: Your experiences?

Here’s an open question to the readers: what have your experiences been with the sizing of binders?

Someone asked me how accurate the sizing chart for Underworks binders actually was. Since I’ve never bought a binder from them, I couldn’t really answer, but it’s a really important question when you think about it.

So, of the binders you’ve bought, how have the manufacturer’s measurement guidelines worked for you? This reader is looking for specific details on Underworks, but feel free to comment on other manufacturers.