Sure, bare copper is sexy but stills work better when wearing a jacket. We all like seeing copper porn but I prefer not to go bare.
Insulating the boiler helps stop the still from heating up the room (which is sort of a big deal in a small apartment) leaving more power for faster heat up times and giving you higher energy efficiency. I use reflective foil bubble wrap for the boiler.
For the still column, insulating keeps heat from escaping the still but more importantly helps maintain equilibrium inside the reflux column. After the gradient of volatiles is established we don’t know to upset the balance. An uninsulated column has no protection from wind or temperature changes in the room. If equilibrium is disrupted, your spirit quality goes down,
I even added insulation to the condenser area to keep the cold in. After reviewing some notes from Odin’s iStill blog, he mentioned that we shouldn’t be insulating the still head condenser area. During my last spirit run, I removed the insulation around my condenser without any ill effects. I suppose passive reflux is only of concern on the reflux column and boiler, and passive reflux should actually help in the condenser area.