I have it. It works. Currently mounted on a Mk 12 Mod 0 type rifle. Check Lowlight's youtube channel for a video review that includes the 1.5-6 and the mount.
I have one on order along with a 1.5-6 DFP, but alas I continue to wait... It's the lower version (.980" IIRC) for use on a FAL. The video mentioned above sold me on it, plus the USO rep gave it very high marks.
It comes in two different heights. The measurements are given on the website but I don't know what that measurement is taken from. I assume its from the top of the picatinny rail to the center of the scope tube.