I have an (I think) 8200 that I got a good deal on. With respect to bikes, I mainly use the stone for shaping things that need a little shaping and use the metal cutoff wheel for cable housing. My park cutters always smash the ends a little bit and then I have to hunt out the ice pick to open them up (and occasionally the file to clean the ends up). The cutting wheel goes through them like butter in little/no time. Not something I need often, but it makes life easier when it's there. I'm about to build another bike that'll have fenders. Last time I did that, I spend a couple hours with a hacksaw cutting down the struts once I was done. Looking forward to that being a much quicker job this time. My wife is trying to take up stained glass, so I got some disks for cutting glass and the flex neck so that she can try using it to cut under water. We'll see how that goes.