There's a little more to a Kirkham than just a pretty skin, the suspension for one thing. About the only thing you could call a disadvantage is the original style frame.
Although originaly not in my sights (or budget), I kept going back the KM site and I finally just caved in. No regrets, even though I spent almost double what I planned on.
Nothing rational about buying one of these cars anyway, might as well embrace the insanity.