Dawson's (current) black rear sights have serrations that leave a plain unserrated gap around the notch and leave a smaller gap around the side and top edges.
Call this "Dawson Style #1":
Dawson's rear sights that include tritium or fiber dots still have the gap around the side and top edges, but the serrations run all the way to the notch with no gap.
Call this "Dawson Style #2" (ignore the tritium):
Finally, most(?) serrated plain black rear sights have serrations that run the full surface of the rear, all the way to all edges.
Call this "Fully Serrated":
If you like serrated rear sights, which style serrations do you like and why? Feel free to comment on how fine/coarse you like them to be, but I'm mainly interested in the coverage issue.