I think the sear box is just a really handy option.
The Firecraft can get up there for temps, but it takes some time, especially when you're in a cold climate like I am.
I do have grill grates from my gasser that fit the firecraft, so I've done that option, but I don't think the heat is a real match for that propane sear box.
The versatility of it seems cool, but not a must have.