One thing to watch for is that some of the build guide for the 12-inch printer hasn't been fully updated. The section on adjusting the stepper drivers, for example, still reflects the trimpot process used with the RAMPS board. Rambo uses a digital/firmware adjustment, so a completely different procedure would apply, should adjustment of the stepper motor drive levels be required.

Early adopters of the 10-inch printer typically found their MEGA2560 & RAMPS to be preloaded with firmware for the 8-inch printer, not 10-inch. The changes to fix this were minor, but it was still a frustration for some when sides of initial large prints were arbitrarily missing. At least with the 12-inch printer, the use of a different electronics suite should help ensure the boards arrive preconfigured with the right firmware.