I've been upgrading an ancient RAMPS-based printer to something a bit more modern. The MKS Robin Nano 2.0 seems to be a well-made basic board that has all the stuff I was using on my RAMPS board, just packaged better. The design is Open Source (or, at least, published somewhere) which is nice because the documentation is a bit sketchy. Once I figured out the wiring, the actual upgrade process was straightforward, if tedious since every. Single. Connector. needed to be remade (if you don't already have a stash of JST-XH connectors and a decent crimper, get them now; I recommend a PA-09), and don't forget to print new mounts before dismantling the old stuff. I can't comment on the MKS-supplied firmware as I built my own Marlin config. Again, the documentation is a bit sketchy, but it's there on github. Micro-SD card-based firmware updates are a nice touch. I still need to do some tuning and try out sensorless homing, but I'm happy with where I am now. The end product is an old printer that's... not exactly whisper quiet, but the fans and hobbed gear digging into the filament are now more annoying than the steppers.