SO allow me to spell it out. When I said "best", I simply meant that the best way to add frame connectors IS to tie them into the floor system. I was not talking about which way of doing THAT was BEST. Are we clear now?
How do you know? You have empirical evidence of how much the chassis is stiffened with either tubular subframe connectors tied to the rails and crossmember or the open sheet metal connectors welded to the floor? Because if you don't have data, you've got no clue which is "best".
Better than what? They're stiffer than these cars are, not a single doubt about that. Does that make them better trucks than the competition? Maybe not, but again, what exactly are we comparing? They have better payload capacities because they weigh less. They certainly dent more easily. Pros and cons, "better" is a very subjective term.