I absolutely LOVE my camera lens! I bought it before last season began and it's worked perfectly for what I do. I researched the camera forums and debated which lens to purchase for a long time before deciding on the Sigma 50-500mm. It's not a small lens, but it's not too big to take on a couple mile hike. If you hunt mountainous terrain or hike super long distances I'm not sure that I'd recommend it - unless you're a professional photographer.
But, when it's all said and done, I still feel like I need more reach. About twice as much would be nearly perfect. Until then, this lens will be the one providing the photos for this blog!