This might sound like a less than serious answer, but it's really not. The best sight system for me might not be the best sight system for you. The best sight system for my purposes might not suit your purposes. That being said, there are some popular alternatives you might want to consider.
Rear sights can be adjustable, or fixed. Personally, I've found that different ammo has a different point of impact with my 9mm XD Tactical, so if you want to hit what you're aiming at, adjustable rear sights are very handy to have. You can easily adjust the sights to match the point of impact for the ammo you're using.
The most basic sight is a black notch and post. Many people still consider this to be the most accurate system as well. For highest accuracy, most would suggest getting a front sight width that leaves only small light bars to each side, which ensures the sight is centered.
Many folks that use their XD for defensive purposes like tritium sights. There are many different variations of these, using tritium on the front sight only, or both front and rear. Tritium sights will basically glow in the dark, so they are easy to pick up if it's dark. During daytime they work much like the white dot sights your XD came with.
Many competition shooters use fiber optic sights on front and/or rear, as these glow brightly during the daytime, and are often easier/faster to see.
Then there are other odd sight systems, including rings and other unusual apertures and designs.
The bottom line is see if you can borrow or try a few different ones, and see what you like!
If I could find somone with these different kinds of sights I would borrow and try them. But the people I know have standard 2/1 dot sights. Thanks for the imput Scott. I am considering the XS sight with the verticle line on the rear sight. Basically I am trying to get a feel for what the members like and I will try that. If I like it great, and if I don't then I will have to try something else.
I think if you will carefully zero the factory 3-dots and practice a lot, you will find them entirely adequate. The only change I have considered for ours is to replace the front sight with a "big dot" tritium (sp?) but I would want to make certain that I could get one in the same height as the factory offering, first.
Some of this depends on your vision, intended applications, etc. If you're a young buck with good vision, about anything should work- but there is really no substitute for having your sights dead-zeroed, whatever they are.
But all my experience is with military style rifles. When I changed my AK's iron sites for a ghost ring system, my target acquisition speed and accuracy went up. Its easier to zero in on the target.
Im going to get a set for my XD because it seems to be the best TACTICAL/self defense type site for close and medium range shooting. I am not convinced this set up would work as well for target/casual or long range, Handguns.
I guess it really depends on what you plan to use it for.
How do you plan to use your XD, Tim? Highest accuracy and fastest target acquisition can sometimes be at odds, as the fastest sights usually are fast because they are somewhat less precise.
Here are some other things I would consider...
What ammo will you use? Will you use different types? Often different weights and brands of ammo will have a different point of impact. This is certainly true for my 9mm Tactical. If you plan to use different ammo, and want your bullets to hit where you aim, that would likely require an adjustable rear sight.
Do you ever anticipate needing to use the XD in low light? Tritium sights are very useful in low light, as is a rail mounted light, of course. If you'll only shoot during the day, the tritium dots may just be a distraction and an expense you don't need.
Do you anticipate using your XD in any competitive shooting? Different types of competition (IPSC, IDPA, etc) have different requirements for what sights are legal, as well as what sights are typically competitive.
What sort of budget had you planned? My personal favorite is a low mount Bomar rear sight, with a Dawson fiber optic front sight, but that requires a gunsmith installation (for the Bomar rear) and can cost over $300. There are lots of different sight systems that you can install yourself with a little effort, that are a lot less expensive.
A forum community dedicated to Springfield Armory XD and XD-M series firearm owners and enthusiasts. Come join the discussion about optics, gunsmithing, styles, reviews, accessories, classifieds, and more!