Neither.
Mine (in the truggy) and my son's (multi-use K5) is quite different than most. They are not "tied to the frame" in the normal sense, but rather they bolt to the body mounts on the frame. For most applications, I personally don't care for the either the normal "tie it to the frame" or the "bolt to the floor" approaches. They each have their place, but I think there are better ways for most of us...
The truggy has a square tube subframe that the cage is attached to. The subframe sets on the factory rubber body mounts and uses factory fasteners. The cage bolts to the subframe. And the "body" (floor, cowl, windshield) bolt inside the cage/subframe. So, "body" bolts inside cage, and cage is mounted to frame; the body never touches the frame.
My son's is not so radical, but neither is the use. We cut out the factory body braces where it sets on the body mounts and replaced it with welded in square tube (instead of the stamped sheet metal factory braces). The cage and rock sliders (raised up so they go through where the lower hinge used to be) tie into those beefier floor supports.