One thought about the e-track:
Using bonnets like this, the force is pulling directly up on the relatively small screws that hold the e-track to the deck.
Typical tie downs usually have much larger bolts, and tend to be pulled sideways a bit, so they're more in shear (which is good)
I guess that there's enough small screws in the e-track that the force is distributed and should hold up well enough, but it just makes me wonder a bit...
I don't have any particular experience either way with the e-track, but have been considering installing it in the toy hauler. Also concerned there with the raised edge + kids with bare feet!