Comparing lenses

[ajfetzer]

Hello Everyone,
I am researching new lenses and wondered if anyone can tell me how to compare the same lens between brands. For example I am looking at the 18-200 mm f/ 3.5-5.6. This lens is available in Canon, Sigma, and Tamron brands and there is a significant price difference between the three brands. How do you decide which is the better lens, besides reading reviews which seem to be subjective.

Thanks

[DesignerDigitals]

I never buy off brand lenses as the quality of the lens is not as good. Yes the cost is higher but you get what you pay for.