Make it three. I'm on the third battery for my darter pro: twice so far, the battery has swelled up and made the keyboard buckle. System76 support consists in selling me replacement batteries at a serious markup.
I've decided not to install the third battery, so I have more of a desktop now.
FWIW, the Ars reviewer installed COSMIC on a Framework and seemed to really enjoy it. They even sell a mini case that transforms their laptop into a desktop.
I've decided not to install the third battery, so I have more of a desktop now.