Honestly, yes, re energy density. I hadn’t seen home batteries in-person until a couple of years ago. I was surprised by how small they could actually be (still with a decent capacity). I’d totally trade some of that for chemistry with a less… catastrophic failure mode, and I don’t even have a big house, even for non-US standards.

Not speaking one way or the other on sodium ion’s properties specifically. I see from sibling comments that it’s not straightforward.