I started using the Novak Ghost Ring rear sight bases several years ago on a number of compact & subcompact pistols.
The only pistol which still has one is my 4513TSW, and only because it also has a single tritium capsule installed in the bottom/center of the rear sight. The other pistols on which I used them only had front post tritium capsules and plain black rear Ghost Ring sight bases.
The non-night sight Novak Ghost Ring rear sights are fast and easy to use in some respects, at very close distances, although they do take some adjustment.
The top of the front posts had to be 'leveled' with the top/sides of the Ghost Ring's wide aperture, and the front sight post dots made such positioning
interesting in the respect that the front sight post dots were below the top of the sight picture, but above the bottom of the rear sight's wide, shallow notch. Naturally, this gave a different POI than when someone would center the front dot at the bottom of the rear aperture, or at the top of the rear aperture, which I saw the occasional person do when trying to use the sights.
I eventually replaced the Novak Ghost Ring sights with regular Trijicon & Ashley sights on all but the one .45 pistol, and that was because Novak finally came out with the single tritium capsule-equipped .45 rear sight base and I installed one in that pistol. "Stacking" the front & rear tritium capsules, but with a sufficient amount of space between them, permits
me an acceptable low-light sight picture, and I've become accustomed to the slightly less easily seen front sight dot's visibility during ordinary lighting conditions, making the sight picture appear more like half of a rifle aperture sight picture, without the dot to distract me. A white vertical line in the front sight would be an interesting idea, though.
I might've liked the other non-night sight Ghost Rings if I'd installed plain black front sight posts on the pistols, or simply blackened the painted white dots.
Since they were advertised as only being intended for 'defensive sighting' at close range defensive distances, they will probably satisfy the needs of many folks who choose them for that purpose. On the other hand, when I had them on a couple of 9mm pistols which were capable of excellent accuracy when equipped with standard 3-dot sights, I started to miss the ability to make longer range shots with the same inherent potential accuracy ... meaning 'precision shots' at 20-35+ yards ... and changed back to 3-dot night sights for the more precise rear sight notch dimensions, as well as low-light illuminated sights.
Deliberately aiming at 'reduced size', intended target areas on a standard silhouette could sometimes take a bit more effort and time, especially at 10-11 yards ... but COM at 3-7 yards was easily acquired.
I guess I'd have to say that these are decent sights for an intended purpose, and each potential user will have to determine for themselves whether it meets their perceived and anticipated purposes.
They might be easier for some folks to use than the "Dot-the-I" express sights, though ... or maybe not. The older Ashley Big Dot I have on another .45 pistol has its own interesting requirements for sighting at different distances ... but it's really big, easy and fast to visually acquire when rising into my vision plane.
