Best XP/Money ratio in the game, simple as. If I want to make money while training combat I'll kill abyssal demons, Made 6M from one trip the other day (Of about 200 demons) so it's not as if It's bad money. And with the new clues you can get lucky and make a few million off them. I'm not even 85 slayer and I kill abyssals all the time. After I've finished using my current pies (150 left or so) I'll be getting 85, but that won't be until some time next year.