The best part of it is that I no longer have to spend hours on making reports for our clients. You just make a template, create a data source and it's done. It's one of the best tools Google came up with in the last years.
It's very easy to use and extremely intuitive.
Could use a couple more integration (Facebook for exemple) but hey it's FREE and it's very very good.
GDS is free and that is its greatest strength. It connects easily to Google services, and supports a smattering of other data sources. It is easy to use and has some power under the hood that isn't obvious at first blush, especially with recent updates that permit better data aggregation and transformation.
It is very good for relatively simple dashboards, but if you are looking for larger scale "enterprise" tools or want more flexibility in data management, it's probably not a good fit. Maintenance of dashboards is highly manual and it is nearly impossible to create template reports or duplicate them for other similar data sources.