From my related question, it turns out cryo tanks are not double-walled for insulation purposes. So now I will continue along a similar line and ask, aren't cryo tanks heavier than normal tanks on a per surface area basis?
A normal tank would be one for kerosene or hypergolics---room temperature normal pressure things.
My thinking is that the extremely cold conditions of the tank would make them more brittle or structurally weaker somehow, so they'd hafta be thicker to be stronger. OR they could have some other insulation besides double-walls that weighs them down.
You can pick either LOX or LH2 tanks. If there's some major structural difference between them, well then I'm actually looking forward to learn about it.