That's the same way my Dawson is, It's undercut to allow more light for faster target acquisition plus the fiber optics really stand out at the outdoor range..
For self defence it's no better or worse than the factory front sight..
Here's the link to Dawson's Sights..
Rear - http://www.dawsonprecision.com/Glock+Black+Serrated+Rear+Sights
Front - http://www.dawsonprecision.com/Glock+Front+Sights
I have been told by others on the Long Slide Forum that there front sight is shorter & doesn't overhang the cut out in the slide the way mine does BUT there light pipe is shorter & there for not as bright..