Yesterday I got to do farmer's walks with the Elite FTS handles.
The narrow grip makes it "easy" to grip, but the thick barrels make it hard to walk easily holding them. They're relatively easy to plate-load, as well, but like a deadlift you have to prop up the "torpedo" to load it.
Coincidently, I read this post from Jim Smith explaining some techniques for extending your farmer's walk distance.
You certainly don't need these handles to do farmer's walks - anything you can pick up in two hands and hold is good for farmer's walks. Dumbbells, barbells, sandbags, buckets of water or sand...I've even farmer's walked with subcompact wheels gripped in each hand. But if you've got access to these "torpedoes" they're worth trying, both for farmer's walks and for deadlifts (see that Elite FTS link).