I absolutely love the FFIII, and I've never had any issue with the performance of two on two different turkey guns. Recoil is not a problem. The only complaint I had was the battery cap. It can be frustrating when changing. I broke the threads on one. Burris promptly sent a replacement no questions asked, as they have one of the best warranties in the business.
I know several friends who have all good things to say about the Vortex Venom, but I have no personal experience. I believe it has a slightly larger/wider field of view.
In a nutshell, I don't think you can go wrong with either. I also find them far superior to the old fiber optic type sights.