As I have seen that Europe sometimes uses external starter preheat non-integrated CFL fixtures intended for PL-L and 2D CFL lamps and that Japan makes heavy use of preheat non-integrated CFL fixtures that use external starters, I have noticed that very very few preheat non-integrated CFL fixtures intended for the North American market make use of external starters? Why is this so? Personally, I would find that having preheat non-integrated CFL fixtures that use external starters would allow for better lamp and fixture reliability because if the starter fails and the lamp still works, you can simply replace the starter.