I'm not sure exactly why (I think it's the new food system), but clearing crypts seems much faster now, even with the antler pickaxes. I didn't even make the bronze pickaxe, I just took all three of the antler pickaxes and had no problems.

If you have a bronze pickaxe, that would make an okay backup at first, but it seems so much faster and easier for me to mine iron than it is banging away at rocks to get bronze. Might as well just go to straight to iron.

Durability aside, you're going to want fully upgraded iron pickaxes if/when you start building with stone. Pounding rock is no fun, so spending a bit of iron to make it faster is well worth the effort.