Choosing a countertop edge depends on the functionality of your counter as well as the style that you are looking for which suits your room. You might use a creative combination of edges for a grander decorative look!
Rounded edges such as Double Round Over, Demi Bullnose and Full Bullnose are suited for high-traffic areas more. Rounded edges are safer with children traffic.
For more modern styles, Square, Eased or Single Bevel edges are used since they provide clean lines and sharp angles. For vanity granite tops in master bathrooms Eased or Double Round Over also show style.
Complex edges like Ogee or DuPont will show off the look of a classic style because of their grander appearance. Old style kitchens with architectural features such as overhangs will all be flattered by the curved natures of these complex edge profiles and the different countertop colors available.
Kitchens that are traditional in style can use modern, straight edges for their counters. Modern kitchens can use quarter round edges instead of more angular edges. There are no real rules. It is up to you. A designed kitchen in one style does not have to have an edge profile based on that décor. Especially if you like another edge profile better.
The simple rule is that simpler edges require less maintenance. Keep in mind dirt and dust collectng in grooves of some edge profiles. Keep more complex edge profiles in zones of low traffic such as a bathroom vanity top.
As a general rule, the more complex the edge profile, the more work has to be done getting it right, the more cost.