Bought a Fastfire 3 at the start of the 2013 turkey season. Halfway through my 2014 season it started cutting in and out me. Sent it in to Burris and they sent me a brand new one in about a week. Made it through the 2015 season fine. Halfway through the 2016 season the second sight started doing the exact same thing. Sent it back into Burris, they sent me another. So both sights only lasted ~1.5 seasons before I ran into issues. It seemed to be something electrical with the battery connections. Sometimes I could take the battery out, put it back in, and the sight would start back working. I cleaned battery terminals, tried multiple batteries, but nothing ever solved the problem. LOVED the sight, but can't have something on my gun that is that unreliable. Malfunctions did cost me a gobbler or two. Luckily Burris's customer service is top notch.
I ended up selling my fastfire and buying a Venom. Just installed it yesterday. So far so good. Adjustments performed exactly as they were supposed to. Hope it lasts longer than the Fastfire, but if it doesn't, I have heard nothing but great things about the Vortex warranty.
I had the 8MOA Fastfire and much prefer the 3MOA on the Venom. You can also get the 3MOA on a Fastfire if you go that route.