Hi Ryan,
The reason I brought up the DX/FX issue is because early on in this thread, folks were discussing the focal ranges of various zooms without taking note of the fact that one of the lenses under discussion is not designed for the consumer cameras with the small sensor (DX) and that the performance you get with that lens on a DX camera will be different than what you might expect, if the only thing you look at is the focal range XX-XXXmm.
Perhaps the easiest way to put it is that if Greg takes his DX camera, and puts a DX lens on it at 200mm (as marked on the lens barrel), the field of view that he gets will be wider than what he gets with an FX lens on the same camera, also set for 200mm. For the same given setting (as marked on the lens barrel), the FX lens will provide a tighter shot (longer telephoto).
Those who have the components can try it easily. Take a DX body and put the 18-200mm DX lens on the camera at 200mm. Shoot a picture. Now switch to the 70-300mm FX lens, set it to 200mm and shoot the same scene. For a given, marked focal length, that FX lens has more reach.....1.5x more.....than a DX lens.
/Kevin