I ended up using "Fixed Zoom" instead because it has different behavior that I prefer. But I give "Default Zoom" five stars because it does exactly what it says it does.

The reason I ended up using "Fixed Zoom" instead is that I always want the initial zoom of pages that I view to be 125%, even if I changed the zoom level manually the last time I was on that page. Sometimes I want to temporarily adjust the zoom level while I'm on a page, but I still want it to be 125% when I reopen the page.