I've been a member here for about 4 femtoseconds, and have used Screenshot Captor about 4 times since I installed it today.
My very first impression is good (I'm looking for something with the editing power and ease-of-use of PicPick), but I'm very surprised that the option to open my screenshot directly in the application's editor is so cunningly hidden.
After carefully perusing the 'Preferences' with no luck (I would have thought that 'Interface Options > 'After Capture Show', or 'Post-Capture Options' would have been the logical places to put 'Internal Editor'), I continued my quest.
After some time I found the 'After next capture:' drop-down menu and thought I'd try the 'Show main window form' option... Eureka! :-) That opened the editor despite the description not being very intuitive.
Anyway, I thought I'd share that as I'm sure there are many new users who also would like to open their screenshots directly into the editor but find locating the correct menu item quite difficult.
Here's to Screenshot Captor and I hope I find it to my liking after a few weeks of use.