I just used this template and it's very nice and polished. If you watch the tutorial and use the suggested number of images (I believe it's set to 20 images), it's a cake walk to make a really wonderful show. If you want to add more, then there are slide styles which you can use for the additional images.
The "adding additional images" part is a little more cumbersome (though not really that bad). The slide styles contain a number of image layers (9, 10, or 20) in which you need to populate with images, even if you are just wanting to showcase 1 or 2 more images. While adding in a few more images isn't too bad, let's say you want to add in a lot more (15 or 30 for instance), then that would take some work to get these slide styles to do that (bc with each slide you add where you are just showcasing 2 or 3 images in that slide, each one, you still have to populate with say 9 images). It would be ideal if there were more slide styles included that could handle 10, 20, etc. more images and be grouped together with effects that can easily work with the main show.
I really did enjoy this template and am very glad I bought it. One tip I found is that if you intend to add video, you may be better off doing that as an additional slide (so that the video will never be linked to any of the other template slides).