Neither is a good option for an established company — in that situation your app is likely too large/complex to compile quickly on a mini and the legal grayness associated with hackintoshing makes that a no go.

At work I just use an external KB while I’m working at my desk (98% of the time), rendering the macbook’s internal KB almost entirely moot.

I agree. The Mac Mini is enticing as a build server because of its price and form factor, but goddamn does it feel slow. I suppose a Mac Pro would be a better choice but they are so much more expensive.