I guess it comes down to budget. I have owned the older 2v v10 and recently stepped up to a 2009 f350 v10 with 4.10 gears. Without a doubt it feels like it has more power than the older V10. It's rated to pull 12,500 bumper pull and 14,500 fifth wheel.
Now if you can find a 6.2 with the 4.30 gears for the same price I would say drive them both check out the creature comforts and go from there.
Either truck will get to the top of the hill within a few seconds of one another. They both have engine grade breaking. So I would go with the one you can get the most bang for the dollar.