If you want a griddle for browning or searing, get the heaviest one you can find.
I have three, one is the largest Little Griddle brand, one is a smaller Little Griddle that's completely coated with a tough nonstick material. Another is from GrillGrates and is just thin flat metal.
I don't use any of them in my pit; only on my gas grill. They're fine for teppanyaki, eggs and bacon, burgers, French toast and other light grilling. But none is heavy enough to properly brown smoked or sous-vide meat.
I'm done buying griddles until I can find a really heavy one that will hold heat like cast iron and has a nonstick coating that is metal utensil safe, like the various ceramic compounds.