These sights are awesome. As said, they are not meant for target shooting. for instance most of your small, precision-pistol targets will be obscured by the front dot.
However; if you get a man-sized silhouette or any of those threat targets (with a picture of a bad guy), you will find that this sight will allow you to put a round into the A zone faster than anything short of, say, a docter Optics holo sight. The holo sight is usually a bit hard to conceal and subject to breaking in a scuffle. Therefore, imho, thes sights are some of the fastest you can get. Putting the big dot on the "i" is much easier and more natural than lining up the front sight between the two rear posts.
If you're going to compete, I don't think they'll have the precision you want, unless you are doing some sort of action shooting (IDPA, etc...). If you are looking for speed, I think you'll like them.
CWB (ajamesp51 installed mine, give him a call)