well you asked , the power wagon is built for heavy duty work application , the Tahoe for towing and not as hard off road use . i base that on the fact that power companies use the power wagon for line work ( off road ) , surveyors used to use the tahoe/suburban for their work but most have switched to pick up trucks , i only know a few but they said the newer ones just didn't do well off road not enough ground clearance ( GC )!
that being said i had a Tahoe it was good on the beach but not as good off road in mud or trails as my dodge GC , it dragged alot ! towing i have used both and a suburban also , a 4 door pick up ( and i have had 5 ) will out tow any Tahoe / suburban made , one was a Chevy and it would out tow the Tahoe ,
your ? is not fair for the Tahoe , you are taking a vehicle made for a different job and asking it to compare to a work truck , the Tahoe is a smoother ride , maybe safer in a crash , better mileage , the dodge has 456. gears would pull the hinges off the gates of hell but won't pass a gas station ! the dodge is made to haul loads over rough ground and has more GC and 33 inch tires from factory ! now the power wagon has front and rear locking diff's and anyone with a clue will tell ya that a vehicle with that and more GC will out preform one with out off road ! did you know the power wagon comes with a factory winch installed , the switch on the dash is labeled H-2 recovery ! ( couldn't resist )