Re 'Actual Size' ... doesn't actually work the way one expects when moving through multiple images of difference sizes.

If you choose 'Actual Size' and then tell it to remember the zoom level, it just locks the window size. If the next image has different height or width in pixels, it is zoomed up or down away from its actual size to fit the window, when what should happen is the window gets resized to suit the new image size.

Sadly, this is something I consider a paramount feature in any image-browser, and absolutely NONE of the ones available for OSX (including Xee) does it. Even ACDSee for Mac doesn't have it, which is bleedin' daft considering its Windows parent has had it since version 2.1.