The look of the modern milled class is actually similar to the clasp on TAG Heuer's heritage Autavia remake bracelet. Which is also done in full high polish. I think if one wants the original 60s Heuer vintage look, high polish is the way to go.
For my taste, I also think the Panda looks better with the high polish. But if I was buying the bracelet for a different Carrera, the brushed/polish combo might give a better look. For example, the Red Carrera might be a bit too blingy in high polish as the dial is already eye popping.
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Full High Polish
Brushed/Polished Combo