Thanks for the compliments guys! Using a Canon 7D with the Sigma 150-500. Lens is about to go out the window, I hate it. Leaves stuff so soft and doesn't focus very fast.
I'd heard those comments about that lens, which is why I went with the Canon 100-400. I think it was more expensive, and you lose some reach, but even though at 400mm it's not as sharp as it could be, I think it still has superior quality to the "Bigma."
Plus, with 18MP to work with on the 7D, there's more room for cropping, if necessary, to make up for the lack of reach to a certain extent.