Well, I can see daylight through where my doors and the top should be sealing, so it's extremely drafty. My commute to the office from home is like five minutes, so there's no time for the car to heat up. My main issue is the elements that are making it into my vehicle, especially on my way to work... not fun selling Land Rovers while my left side is soaked.
I'm more interested in a truck type hardtop. Halftop, whatever it's called.