Any problems with these?
No problems. The sights were fine both in fit and function. The tritium is as bright as the Trijicon sights on my other guns though not as bright as the Meprolights on my Kimber.
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Didn't you like them?
I expected too much from them. I still wanted to make precision shots at midrange (for pistol) distances and I couldn't execute those as well as I could with post/notch sights. I know the advertisements from XS say that it is possible. I just couldn't or wouldn't put in the time to practice it when I could do it easily with standard sights.
Do not get me wrong. That big dot jumps out at you for the real close range work but then again, as some pointed out in the past, it is possible just by point shooting or no sights at all. I wouldn't say they are worthless or even to claim the opposite, that they are the ultimate sight system. I understand that they work for a few people and not at all for others.
Sorry for being longwinded but I think you should know all this before you buy these and have high expectations.