brent
The main appeal is repairability but its more than just that.
You can choose to buy it with Windows or no operating system. They have official support for Ubuntu LTS and Fedora. You can buy it with or without storage, with or without RAM. Buy it pre-built or just the parts and build it yourself to save money.
It is modular so you can decide how many USB ports you want and of what type. If it has ethernet or a headphone jack or sdcard slots or a num pad. Change your mind later? Just buy the part you want and swap it out as simply as a video game cartridge.
You are able to purchase replacement parts for everything. You can upgrade the internals without buying an entirely new laptop as they try keep it compatible with the old design.
There is a lot to like but they are significantly more expensive than their competitors.
