I have a set (different manufacturer) on a rifle. Shooting half sideways is a little weird at first, but actually not as awkward as I thought it would be...and still seems to be accurate. Who'd a thunk it?
They should line up at the same distance from the bore as standard sights, actually really easy to use, just tilt the rifle a little to switch between the magnified optic and irons. This way unlike co-witness sights, you have an unobstructed view of both the irons and optic, can switch quickly and easily between them, and if the optic is obscured, it doesn't block the irons like co-witnessing does. Some run a small reflex isight at 45 degrees for the same reason, so they can use that up close with both eyes open, and use a higher powered magnified scope at distance.
I considered these awhile back, but I'd like to try them out first. I worry about the rear sight interfering with the charging handle when the rear is folded flat (see the video at :25).