Easy to install, very compact and simple. The best thing though is the support. They're open to suggestions and implement them quickly. I don't mind at all paying a small amount for extensions where you get this type of support. seems much more than fair. I wanted to see support for flickr tags added and they told me it'll be in there in the next 2 weeks or so! Thanks guys.
The ability to show any sort of set of photos, be they in picasa, flickr or even a directory on your hard drive is the most handy thing for my implementation where i don't know how article writers will submit their photos.