That interesting on the ceramic belts must order some of those. I have a silverline electric one but never use it now it's just sitting here gathering dust.
I use a smaller air file for getting into car chassis etc but the blue zincronium belts wear out extremely fast.
I have one of the Evolution ones that I purchased 2nd hand from a forum member. I was not looking for one so bought on a whim.
It is nicer to use than a grinder - less noise, less dust! It can also get into places the grinder can't and be easier to control. I have to force myself to use the grinder sometimes as I am conscious that the belts have a lot less life than a disk.
It's not as versatile as a grinder as you can't cut/chop things, but a really useful tool.
My last job with mine was shortening and polymer shotgun stock. I was filing it to keep control, but that got tedious and I resorted to the power file which did a good job.