It's the same as a scope that is on 1x. For me, its noticeably sharper than using a red dot. Plus there is no color change looking through the lens like a red dot has (some dots more that others). I can shoot both eyes open with mine.
Although I'd argue that the bdc was unusable in the Burris AR1x I had. Center dot completely covered targets as well. Went back to leupold prismatic and eventually Vortex Spitfire AR. Owned aim point t1, eotech xps, holosuns, primary arms t1 clones, and trijicon fiber optic and led dots. All except the holosun 510c is gone. For some reason, the dot is nice and crisp while every other red dot for me isnt. The fiber trijicon was crisp, but the image was so blue.