So I want to buy a 150-ish mm lens and for my current budget I can get a 150CF or a 160CB. The end use is travel, portraits handheld and for close-ups with tubes. Any particular reason why I should pick one over the other? I have a 80CB and am very happy with it so I don't have any issues with getting a CB lens. As far as I can tell, besides the insignificant focal length and aperture differences, the 160CB is perhaps a bit lighter, will have the easier focusing that the newer lenses have and...that's about it? I intend to use the lens handheld and mostly wide open. I'm leaning towards the 160CB simply because it is newer. Is there something I'm missing? On the other hand...an old 150CT* is half the money of either of those lenses... Thanks for any opinions!