It basically boils down to whether or not the rims are coated.
If they are, then of course bead blasting would remove that coating and take you down to bare metal.
If it's not, then bead blasting would not be removing anything, and you'd be left with bare metal.
From what I was told, the H2 Stock Rims are already bare metal.
With that said, I'll probably be getting mine done by a friend for free, and I'll have him bead blast them "just in case". If I were paying, I'd go with whatever the Powder coated suggested, and is willing to warrenty.
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North Texas Hummer Team Member
2003 Red H2 equipped with Tough Country Heavy Duty Armor Series Front End with Winch, Rear Bumper, Brush Guard, and Roof Rack.