Sights are truly a personal taste thing. There are dozens of choices. One of the most important thing in terms of visibility is the size of rear notch. Especially for those of us with aging eyes, a larger rear notch often works better.
Second, think about the design of the rear sight. You want your eyes to be drawn to the front sight, not the rear. That is why I absolutely despise Novak sights -- because the rear sight is very busy and it draws your focus to the rear sight. Yes, I have them on one of my guns, and I absolutely can't stand them. See how complicated the Novak rear sight is:
Also, see that curvature on the rear of the Novak sights? The problem with a curved surface is that if the sun is coming from behind you or from either side, it will pick up the light and you will have a bright spot on the rear sight reflecting the sun. It isn't very noticeable in that picture because of the subdued lighting, but it can be a real pain out on the range. You can see it a bit in the picture. Notice how the right inside curved portion of the rear sight is lighter than the left, and how the left outside curved portion is lighter than the right outside curved portion? The photographer used very careful lighting for that picture, with filtered light from two different directions to minimize reflection, but the reflection is still there. You won't have that luxury on the range.
Now look at Heinie
and 10-8
See how the serrations reduce reflections? Look at the 10-8 photograph above. Looking at the rear of the slide, you can see how the right rear of the slide is reflecting light back at you, but the sight is not (the predominant lighting is coming from behind your right shoulder in that picture). With that kind of lighting, the rear of the Novak would be reflecting light back at you from the left curved portion.
I prefer either Heinie or 10-8. Personally, my next sights will have a ledge, so that I can cycle the slide easier with one hand, if necessary. But if you prefer it, the Heinie is available with a ramped, non-snag rear sight instead of a ledge. The Heinie shown above is a ramped sight. Here's a 10-8 sight with a ledge:
You can get the Heinie or 10-8 sights as nightsights, with a tritium insert on front, or front and rear. I'd go with just front, but that's again personal taste.
