I have been using Grab for many years on a daily basis to capture puzzles from my digital newspaper for printing and solving during breakfast. SnapNDrag should be a part of future versions of mac operating system because of its ease of use and extra features. The extra feature that I expect to be using is folders for grouping screenshots for projects. It will be very useful when working on multiple projects. Instead of screen shots being scattered all over photos, they will be grouped and renamed (easily) in folders according to projects.
Fan of RPN about SnapNDrag Pro Screenshot, v4.1.6