When it comes to optics mounts, you can usually have QD functionality or light weight but not both. The new Scalarworks LDM, or Low Drag Mount, for the Aimpoint Micro series of red dot sights appears to offer both.
Scalarworks claims that the LDM is the lightest Aimpoint Micro QD mount on the market and at just 1.33 ounces for the absolute co-witness version and 1.38 ounces for the lower 1/3 co-witness model, that is easy to believe. The LDM features a clever, notched thumb wheel that is retained by a ball detent. It looks like you could easily witness mark the correct notch to ensure that you always set the same tension when reinstalling the sight. The thumb wheel set up is also very low-profile and actually nested into the mount itself to reduce snagging.
There are a lot of good ideas in this mount. It will be interesting to see if Scalarworks can expand these design elements into other optic mounts. Check out the Scalarworks LDM.