I think the great advantage to abrasive machines is that it is probably the one type you don't need all the gear for. In a metal shop, an abrasive machine is useful for a ton of stuff, and mitres can be easily shot without any cross slides or vises. It takes a little practice, but say 5% compared to learning to weld. If one is going to go to all the hassle of all that gear, I think one should have a cutter based machine, since it does not have the problem of dust. Quality abrasives release a lot less dust than the cheap ones, but there is still that. I use mine out of doors, it is just on casters. I have the option of using a milling machine to do miters, but it takes so long to set up, I prefer to run the abrasive machine.
However, most forums jump all over abrasive machines on the grounds of the dust, or the usual arguments that it is easy to make mitres by hand, which is also true.