I recently sent my CZ 40 to Bo Wallace at XS Sights for developmental work on fitting their "Big Dot" brand of sights on the CZ 40 line of pistols. I received it back today and am incredibly happy with these sights, they are head and shoulders above the factory sights.
One of the biggest complaints I had about the CZ 40 was the small front sight post with almost no dot to speak of. It was slow to acquire and dissappeared in low light situations. Yes, I know a lot of you are going to say point shoot, but I like to be able to have a sight picture if I can. If you want sights you can always see, I highly recommend these.
The tritium is very bright. Bright enough that my neighbor could see them while standing behind me and looking over my shoulder from about 4 feet away. The front dot glows and the rear line glows. These are the 24/7 models, others just have a glowing front sight. The sight picture is "dotting the i" with the rear line being the bottom and the front sight being the dot above it. The sight picture is the same day or night, the only difference is it is bright white in the day and bright green at night.
The rear sight is a very shallow V, making it even faster to acquire the front sight. My first groups were low and more loose than it typical for me. After about 50 rounds I got the hang of the new sight picture and was shooting about 2" low at 30 feet. Another 20 rounds and I was pretty much dead on, but the groups are still looser than what I had before. I am positive this is due to my adjusting to the new sight picture, though, as the groups are getting tighter quickly, I just didn't have much time to shoot it today.
In short, these sights have turned a very good pistol into an excellent one. I'm considering having this modification done to my Beretta 9000S as well.
