They're very useful for reclaiming scrap, big rusty odd shaped and knarly unidentified metal doesn't bother them much, and you can leave them to it.
But don't think they're just for rough stuff you can also do very fine work as well and get a very good finish, and of course they love slotting!
I have a 10" and may already be outgrowing it, a much bigger one would be really nice but space, power supply and running cost of bigger a motor may prevent that, I certainly wouldn't want a smaller one.
But be careful, steer clear if you're at all easily hypnotized..... :biggrin:
Bernard