I like that it's easy to use, has an intuitive interface with excellent documentation for both new users as well experienced ones alike! The support team are also very helpful when you have issues or questions relating their product/service - they're always willing help out at any time of day no matter what your location in relation to them (which can be hard sometimes!).
There isn't anything really bad about this software so far but if there was something i could think off then maybe adding more customisation options would make sense? It allows me to easily upload images from my computer into one place which makes managing galleries much easier than having multiple folders full of photos etc all over different websites / blogs across various platforms such as Wordpress & Squarespace.