In the videos below, she gives her thoughts on both GIMP, and Shotwell. Shotwell is installed by default with Ubuntu, and GIMP is just a one click download from the Ubuntu Software Center.
For more videos of SnapChick going over the Gazelle Professional, go over to this page I did a few weeks earlier. That page I did will also be updated for these videos, as it seems that that page is now the hub for all of this.
So without taking up more of your reading power, the two videos are below. I know I was kinda late on this (the videos came out two days ago), but as they say "better late then never," right?
SnapChick uses GIMP on Ubuntu
SnapChick uses Shotwell on Ubuntu