alleyrat58 wrote:You will get the same temp stability out of 1/4". Once the metal is hot, it'll stay that way for a while.
That said, with a 1/2" baffle plate it will take longer to heat up and the extra mass will take more fuel to heat up. It will also add a lot of weight to the smoker and make it that much heavier if you want to move it around. If it were me, I'd spend the dough and buy a piece of 1/4".