If you modify an Outlaw a bit, the fuel requirement go down a bit. All I've done so far on mine was to extend the chimney, flip the charcoal tray, add a few thermometers at grill level and toss in a charcoal basket, and it works fine. I'm going to be installing some fireplace gasket on mine this spring and that should improve it even more.
Toss in a couple of Traeger rib racks and the Outlaw will cook 16 slabs of ribs and a couple of BCCs at once so it's quite a workhorse. The Outlaw is also really good for grilling for a crowd and if you can find a big enough rotisserie it will even handle a whole small hog or lamb.
On the downside, it's tough to find a big enough cover and a sturdy enough rotisserie for the Outlaw, but that's no problem with a Smokin' Pro.
The only real question left, then, is do you need all that extra grill space?
Unlike propane, you'll never wake up scorched and naked in another county because you mishandled a bag of briquettes.