Pros : It gets the job done. I needed a sander and didn't want to deplete all my savings on a lap grinder or a larger professional machine. This can do large, small, whatever you are looking to do.
Cons : It is extremely loud for one. Earplugs are a must. The belts are constantly falling off the side and jamming into the plastic, smell terrible and the belt gets ripped up each time. It doesn't fit any other belts but GRYPHON belts. The belt is never consistently wet and I am not sure what that sponge at the bottom is actually supposed to do. It certainly does not keep the belt welt all across or with any consistency. I find myself overfilling and getting soaked while using this machine. I wear a bandana over my hair, my safety goggles, and a printmakers apron so I don't get soaked. Otherwise it runs dry. Not good for breathing in airborne glass particles first of all and gets the glass hot-that's a no no! Overfilling is way better than running it with a dry belt. The belts wear out quickly but they are not diamond so that is a given.
Other Thoughts : I have found that I have problems with my ring saw too. They are just made junky on this level. It is a shame, because you pay a lot (relatively) for what you get but it is necessary. I don't have the money to buy a huge professional sander at this point. But the companies know that if you want to make a quality, professional product on a hobbyist level, you need to buy these things. So I would say to get it if you are a hobbyist, but be prepared for the faults. You won't be beaming about your purchase. Undoubtedly you will dislike cold working as much as I do after listening to this thing drone on while you are using it, after you have adjusted the belt several times because it went flying off to the side. One thing I will say that is very positive about Gryphon is that their customer service is great.