I grew up with all-black sights, and with the right lighting believe they produce the tightest groups.  Still, they are essentially target sights.  Especially as my eyes aged, I found white outlines or dots a great aid to shooting fast.  I hated early night sights because they were just muddy dots without clarity. 

Modern night sights are sometimes still muddy dots, but most companies, especially aftermarket, have learned that people need more than a glow-in-the-dark dot, they also need a clear focus in lighted situations, and so they've surrounded their illuminated dot with circles one can see in daylight or in lighted buildings.  Many of these are quite good, but some use florescent colors that prevent a solid focus, as the eye doesn't process florescent properly (I've studied this).  We see it in it's brightness but cannot truly focus on it well, so depending on the color and the presence or lack thereof, the circle surrounding a modern night sight is of relative assistance.

I'm an old dog at this point in my life, have weight the pros and cons, and I have chosen to eschew night sights.  I am rarely--almost never--in places where I could not see my sights to the point where I need a glowing sight.  I always carry a flashllight and use a method to illuminate my sights when shooting.  But beyond that I avoid gunfighting like the plague.  Thus I shoot my guns under illunination 100% of the time, where I still find night sights at least moderately irritating.  If one does use night sights he should have the same sights on all his guns, and most people don't.  Practice like you expect to use your gun, eh?