Roller cam specs

Is there a difference in a roller cam and flattappet cam for the mild and aggressive etc. specs? Or are the specs for them the same if its different what's the roller cam mild specs?

Roller cams generally have a steeper 'ramp', and a longer open-valve duration than what is generally possible for a flat tappet cam.

Duration at .050 is the industry standard regardless of roller or flat tappet, Lift of course is the same. Roller cams can be ground more aggresively yet have more area under the curve. For a more in depth explanation, google "advantages of a roller cam".