We need to start with basic that :
GVWR is taxable rating and you can get a ticket for not paying taxes for the weight you are carrying
GAWR is technical rating and exceeding it indicates safety issue, so in extreme situation the vehicle might get impounded
Also bare in mind that when you have "commercial" on your registration (and in lot of cases you will) - you have legal obligation to observe DOT scales on your way.
My truck has NV registration, who doesn't recognize commercial at all, yet in WA the automated system pulled me over to the scales.