Bolt-on, IMHO, is for mall crawlers with Hummers. Weld-on is a great idea. However, in either case, what's on the other side?
See, if the bolts on a bolt-on vibrate loose, Bad Things happen. Even if not, or if they're welded onto a bumper at random, you're still pulling on the mounting surface, which is gonna make it bend. When you're stuck, you don't want to remove the bumper

... you want to move the truck

... and that can apply TREMENDOUS amounts of force. You want to attached the recovery points to the frame, as solidly as you can.
The CUCV's, for instance, have a 1.5x2 square tube about a foot long that bolts to the frame on the back side. I used the CUCV stuff on my home-made bumpers:
The tubes go through the bumper and then bolt to the frame as part of the mounting. They're welded in front and back plus welded to the brackets I made out of angle iron, so they're not likely to go anywhere.
Anyway, compare that to trying to apply a coupla thousand pounds of pull on a factory-type bumper ... and you have a recipe for bent metal and/or injury or death.
-- A