Positive:

When the addon works properly then it's easy to use, and has enough filter options for my uses.

I do however wish there was an option to store the images in the same order as they show up at the filter screen, and not in the filenames' alphabetical order. Or maybe a "file rename" option or something.

Negative:

Unfortunately the current version (at the time of writing) does not always download all the images on a site. I'm guessing maybe it's an issue with two images with the same filename, or something. Whatever the reason you need to check that the created zip file has the same number of files as you chose on the selection screen.

And depending on how a site shows the images (I'm guessing loaded dynamically or something) then this addon doesn't always detect the images, even with an increased search depth.