Sigma 18-200mm vs Tamron 18-200mm lenses for Nikon D40x.?

I had the Tamron 18-200 a little while ago and was pretty happy with the results. As long as you understand that you are paying for the convenience of being able to use 18mm to 200mm without having to change lenses because the IQ is decent but not great. I used it primarily when changing lenses multiple times was not viable.