consider Tokina 80-200 F2.8? Build quality excellent, solid, like a tank, zoom ring very smooth. Price also affortable. Image is sharper than Sigma, add saturation +1 in DSLR body set up will improve the colour.
some CA in F2.8 @200mm, but not obvious. F4 onwards CA dissapear.
some CA in F2.8 @200mm, but not obvious. F4 onwards CA dissapear.