Main thing I try to aim for is realism and trying to capture the emotion, I don't like fake added colouration

The beauty with diy is that you don't have most of the limitations with just buying a ready built commercial unit, I'll build something, measure and listen to it and simply tweak the circuitry and components until its right.
If a component is expensive but provides better results I can simply buy it without worrying

The only thing I ever have problems with is the cases, one thing us diyers lack compared to commercial is the cosmetics