The 12Pi is a no-compromise design. The features that make it superior are the things that make it a little more difficult to build than other designs. The cooling plug must fit precisely, which means that the driver mounts in the motor chamber, motor chamber fits onto the side panels, and access hole mounts for the heat exchanger / access panels all have to be in precise alignment.
We built the prototype with a table saw and hand tools. I didn't think cutting the fill pieces was all that difficult, but precise cuts for cooling plug alignment are challenging. The heat exchanger provides such a huge benefit in driver performance and longevity, it is definitely worth it.