Excerpt: Recently purchased the 150-500mm for birding/wildlife photography. I am still putting it through the paces to see how it does. So far, pretty pleased. Tripod necessary in low light situations. Have gotten some really great shots of Sandhill cranes and butterflies, optimal lighting conditions.
Pros: Consistent Output, Fast / accurate auto-focus, Nice Bokeh, Rugged, Strong Construction
Summary: I just acquired the a new Sigma 150-500mm lens for not much more than what they go for used...Super Value...especially with case / straps accessories & 4 year warranty. I am a hobbyist and shoot with a Canon 70D. I also have a Sigma 105mm Macro and am very happy with it...
Excerpt: After using the Siggy 120-300 f/2.8 for a few years, I took a chance on this 150-300 f/5-6.3 and was pleasantly surprised. My first surprise came at the weight, specifically how light it was. After lugging around a 7 pound lens, this thing is a breeze and I was able to handhold with no problems.
Pros: Carry Case Strap, Lightweight, Nice Bokeh, Strong Construction
Cons: Lens Creep, Screws Back Out Over Time, Slow Focus, Tight zoom ring
Excerpt: Bought this lens to replaced a Sigma 80-400 that was beyond repair. Should have bought it sooner. I use it mostly for wildlife and birding. It is hand holdable at 500mm at 1/80 second. The OS works great. It's a little on the heavy side but that's the price you pay for shooting long glass.
Pros: Fast / accurate auto-focus, OS, Rugged, Strong Construction