lots out there,
most claim to return to zero but the relatively recent ST article showed most return to within 1/4-1/2" of original POI
They didnt review the Leupold QR system
but covered the usual suspects of EAW, 3rd eye, and a couple of others I forget which
I dont like the design of many and am sure over time the swing off mounts have to give rise to a windage variable as the rear mount settles and or becomes worn.
I like the Leupold post design as there is no windage variable possible as the post drop in.
the clamping force pulls the post into the bore vertically
the only variable that may occur is if dirt or foreign body gets between ring and base but as soon as you tried to tighten them you would realise this.
I like them, run them on four calibres with removable barrels and they all return to zero