I didn't like the Sightmark Ultra Dual Shot QD at all.
Check my posts in this thread to see why.
"The detents on the reticle selector knob do not actually hold the reticle in a fixed position. You can hear the click when turning the knob but the knob doesn't lock into position. It can easily be moved a little one way or the other by touching it or even putting on the neoprene cover.
I knew that changing the reticle would most likely change zero and had planned to stick with one reticle after it was zeroed but it's not even good enough for that."
I would recommend a Truglo over the Sightmark.