Hi, the rectangular region is not remembered between shots, when doing multiple screenshots in a row, which is a usability regression, compared to ksnapshot. Presenting the selected area (as an option at least) would streamline the usability greatly for this usage pattern. Imagine usual assistants and creating shots for the docs: with ksnapshot, you select the region once, and all follow up shots have the same position and size, which was pretty convenient.
The Save&Exit button has a menu with Preferences, where you can change it to remember the region. *** This bug has been marked as a duplicate of bug 365573 ***