Requirements:
- laser printer that works with non-proprietary toners
- USB plug & play on all major operating systems
- Network printing via WiFi and ethernet
- No 2GB bloatware installation required, i dont want your shitty photo management software, just give me the driver
- Replaceable parts
Well, perhaps not the "replaceable parts", but that is doable with a 3D printer. I doubt Brother would come after you for printing a new output tray hinge or custom-colour button set ... and I doubt any other parts are likely to outright 'break' (my laser printers of various brands have lasted around two decades each). Any other parts, such as the image drum, would require too specialized fabrication to be done at home or at the local fab lab.
BR/Script (their PostScript emulation)
ethernet
duplex
And you will be fairly happy. If any of those are missing, you're buying an inferior line.
I currently have a Samsung laser toner (M2026W). I bought it because its farily compact and blends in to my little home office corner in the living room. The duplex machines tend to be a bit larger, a pitty.
Printing - when it works - is pretty good, just the WiFi is extremly unreliable and i end up having to re-configure the WiFi from scratch by connecting via USB and using some proprietary Samsung bloatware. Horrible.