I'm not a fan of fiber optic (FO) sights as they have been shown to break and fall out under hard use, such as during repeated one-handed manipulations in training classes.
I'm also not a fan of the XS Big Dot sights and similar types because the big dot front sight can eclipse the target when shooting at longer ranges.
In my opinion, handgun sights should be made of steel (not plastic like standard Glock sights) and have a distinct ledge on the rear sight, not a ramp, to aid in one-handed manipulations in a critical incident.
I prefer sights like these, from 10-8 Performance, on my handguns:
http://www.10-8performance.com/products/S&W-M&P-Front-Sight.html
http://www.10-8performance.com/products/S&W-M&P-Rear-Sight.html
There are benefits to using a blacked out rear sight with a tritium front sight. One reason we're seeing subdued rear sights and shockingly bright front sights become popular with various manufacturers is that the bright front sight naturally draws the eye to it, where the focus belongs.
Also, with the 2-dot sights or the front-only dot night sights, the user cannot accidentally misalign the sights laterally in the dark (as with 3-dot sight systems) to the point where one of the rear dots is mistaken for the middle dot because the muzzle is so far left or right that the front dot is to the left or right of the entire rear sight. In lowlight and darkness, you only really need to see the front sight post properly aligned on the target in close quarters (3-15 yds) to get quality combat effective hits.
I currently use the Redback One Glock Combat Sights, manufactured by 10-8 Performance, on my EDC Glock 19.