I consider myself an intermediate simmer - i like to fly with realistic flight plans and procedures but i do not want to carefully read through the entire briefing before every flight because i am very lazy.
Most of the info i need for taking my favourite short-haul jet for a ride is visible directly on the briefing page in Simbrief (SimBrief - Dispatch), in the Flight Info, Flight Plan Summary, Load Sheet and Route sections. However, almost anything that has a FMS requires me to enter a reserve fuel amount - and for that, I need to dig into the “Briefing Preview” section (where it is listed as “FINRES+ALTN” in the “PLANNED FUEL” section).
In my opinion it would be a huge UX improvement if that datum was also visible somewhere directly in the Simbrief UI, which contains pretty much everything else I need during FMS / MCDU /… setup.