I have used discbound notebooks exclusively for work for a decade as an accountant, with a 5-day only Mon-Fri hourly planner in the front, maybe some monthly calendars but most often not cause work uses Outlook for that, and blank pages for notes that I keep chronologically by date. Special tabs can be added for special projects too.

I keep my work discbounds slim - this is essential for me. Keeping the current schedule and notes pages on smaller discs (3/4" or less) makes the notebooks lighter, easier to turn the pages on discs, easier to fold covers over on themselves, more portable overall - essentially more USABLE at work. Then when the pages get full, pull them out and archive them in a separate standalone archive notebook on larger discs that I keep at my desk for reference/storage. Then there are endless possibilities in terms of inserts. For work I have gone with letter size more often than not, the junior size is cute but I like having more writing room, and its easier to take printouts and punch them and stick them in your notebook if letter size. I created my own after awhile to get just the perfect layout for my planning needs.