Thanks guys, looks like the 80 grit or so will be the default for now. This fill the gap between my bench grinder and hand sanders and give me somewhere to do non-ferrous metal stuff as well.
Yes, I am aware if the wide world of abrasives and when to use what for my various hand, palm, 1/3 sheet and belt sanders all of which already have various grits and grades on hand for tasks ranging from woodworking to metalwork. As time goes by I will of course expand the belt selection based on the task but 99% of the time this will likely be in the corner collecting dust, but available for use.
For years my go to has been a craftsman 3x18(ish?) hand held belt sander upside down with the trigger locked on. I had to chase that sucker around the workbench despite being on a rubber mat until the belt tracking adjuster broke, so this is definitely an improvement.