Commander, I cant offer user insight into use of this camera but have been snooping around the web comparing a few canons for low light sport. This comment is on a review web page "The EOS 6D doesn't offer the depth of features that its best competitors can, but it combines very good image quality, impressive high ISO performance and class-leading low light autofocus ability (with the central AF point) as well as impressive built-in Wi-Fi and GPS features." This review and others leaves me with the thought that compared to the 5D Mk111 the 6D supposedly wins in low light both in detail (?) and focus ability but it has a less sophisticated AF system. If this is true and AI servo focus in low light is your environment (horse comps indoors) then for the lower price the 6D seems hard to beat. It has a slow burst speed though