First UGH for making feedback for this be in FLOW :(
The mockups such as File:Moon article at 550px wide.png look horrible on desktop, keep in mind that screen size could be anything, and even lower resolution screens might be used in a large format such as a projection. Having almost half of the viewport devoid of content is a huge waste.
I disagree. I have a 24" monitor and I have to resize my browser window to half, to be able to read without moving my whole head left and right. Even worse with tables with a couple of columns but set to 100% width... The above mockup indeed looks horrible but File:03_-_DIP_-_Collapsible_sidebar_(closed).png seems good.
I like the fixed width. It looks great on my 5-year-old desktop and medium size monitor.
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