MNT is entirely open hardware and much more free-software-friendly, right? If you care about stuff like freedom and autonomy in computing, and you have the money to spend, the Reform seems like a far better product to me.
MNT publishes everything: source code, schematics, complete BOMs, mechanical design files. You could produce one of their laptops, or any part of it, yourself through normal PCB suppliers like JLC and 3d print a case.
Reproducing what they have aside, you can also modify any aspect of it by remixing their designs. The most common example of this has been custom keyboard layouts (ergo, split, etc).
Framework is perhaps well-documented, but it's not open. There are only pinouts, partial schematics and some MCAD stuff published for extension development but no ECAD designs.
framework doesn't open source their firmware. despite major demand from their community [0]. they're the only ones among major manufacturers of linux-ready laptops (novacustom, starbook, system76) who haven't bothered to do it. i consider framework to be driven by marketing more than values or honesty