Nostalgic reasons , i kept the bump cowl on the model 2 because to me that is the kitfox trademark, it sets it apart in appearance from other experimentals, you can identify it as a kitfox in a line up of 20 other planes with just the nose sticking out.
Some have argued that the smooth cowl is more efficient, i suppose it is if you could reach speeds where it would make a significant difference,
Some have argued that they can see better taxiing with the smooth cowl, i suppose it is if in tail dragger config. But i'm only taxiing a short distance, the rest of the time im in the air and can see just fine
Knowing that its just a matter of preference, mine is i like the bump cowl better, there is no mistaking it in a crowd
At the risk, i'll give this analogy as well i prefer blondes with a bump cowl as well, because it's just so dang sexy