Do the same math for your carpool...your skid pad numbers would be hard to argue with as well.

So - yes, its a difference, and worse for the bumpers that had larger expanses of metal adding excess weight, and heavier winch ropes, etc...

But my Shrock bumper and Al fairlead/synthetic winch rope set up din't handle much differently than with the stock bumper/no winch...

I saw more difference adding 500 lb of other armor, or the rest of my family (My kids are in their 20's...), on the overall handling, and that weight WAS pretty much centered.

So, of course you are adding some weight, and of course it changed the weight distribution, but the suspension is designed to take passengers/cargo without needing to be replaced to carry them...despite the fact that putting your 6'4" 260 lb son in the passenger seat behind you will change your skid pad numbers by about a tenth of a G.

(I have a G-meter...)