Finally, a subject tailor-made for me!
So, the 2x72 belt grinder may be the second most used too in my shop, just after the table saw. I use it constantly, for a little bit of everything. That is to say, not only do i use it for all the shaping and most of the polishing i do on the blades of the knives i make, but i also use it for shaping the handles, as well as whatever else in the shop i ever need to do any shaping on, as well as other, more random tasks, like sharpening my lathe tools. Its one of my favorite tools to use, its ridiculously fun watching whatever i put to the belt disappear, and the wide variety of available belts makes it extremely versatile.
That said, using a belt grinder for finish sanding, especially in wood, would be an exercise in frustration. This is a tool thats meant to turn metal to powder faster than you can blink, even with a 220 grit belt on it youll still blow through wood faster than youd think possible. Now, rough shaping is excellent, i use a 120 grit belt on my grinder to rough in the handles on my knives before switching over to files and sandpaper, and it saves a load of time, but with the speed the belts running youll just be taking off wood way too fast, and the surface finish would end up less than adequate, e.g ridges, gouges and the like.
Admittedly, you could get around the issues by slowing the grinder down from the normal 4000sfpm range used for metalwork down to the 1500sfpm range used for woodwork, but honestly at that point it would make more sense to just get a woodworking belt sander instead, something like a bog-standard 4x36 stationary unit.
Dont get me wrong, i love my belt grinder, and if you can get your hands on one for a good price do it, but its not the kind of tool id recommend for final finish work. Roughing in is more in the doable range, but be warned that when the belts moving that fast theres a hell of a learning curve, youre going to make a lot more firewood than you would finished product at first. If youd like, im more than happy to post a video showing just how fast one will eat through wood