Framework's modular design has been advertised as a solution to upgradability, which is huge, but I see the real strength in being able to have a GPU plugged in when I'm using my laptop at home, and swapping it out for an extra battery when I'm using my laptop away from an outlet.

Being able to transform the capabilities of the laptop based on your situation is a huge game changer.

How hard is that to do? I know Frameworks are repairable, but you can really do a swap like that completely on the fly?

Honestly, this comment is a somewhat decent sales hook for me; I've been thinking about getting a Framework for my next laptop whenever the current one I use really starts to fail (depending on how their AMD stuff works out), and this comment makes me more curious to look into them.

I don't think anybody outside Framework knows for sure yet (maybe not even internally) but my impression from what they've shared so far is that the expansion bays are intended to be very easily swappable (external, a click & push like the expansion slots) but almost certainly not hot-swappable while the machine is powered on.

They do have some initial specs at https://github.com/FrameworkComputer/ExpansionBay that somebody more knowledgeable than me might be able to glean some practical info from.